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Wikipedia / Orders of magnitude (length)

The following are examples of orders of magnitude for different lengths.

Overview

Detailed list

metres. Metres are used in these tables to provide a common reference point, but metric prefixes above "k" are not commonly used with metres. So for example, 1.21 Gm would more commonly be written as 1.21 million km or (in scientific notation) 1.21 × 106 km. Interplanetary distances are also commonly measured in astronomical units. Distances on the interstellar or larger scale are typically measured in light-years or parsecs.

Subatomic scale

Atomic to cellular scale

Cellular to human scale

Human to astronomical scale

Astronomical scale

1 quectometre and less

The (SI symbol: ) is a unit of length in the metric system equal to . To help compare different orders of magnitude, this section lists lengths shorter than 10−30 m (1 qm).

  • 0 quectometres (0 meters) — gravitational singularity

  • 1.6 × 10−5 quectometres (1.6 × 10−35 metres) – the Planck length (Measures of distance shorter than this do not make physical sense, according to current theories of physics.)

  • 1 qm – 1 quectometre, the smallest named subdivision of the metre in the SI base unit of length, one nonillionth of a metre.

1 rontometre

The (SI symbol: ) is a unit of length in the metric system equal to .

10 rontometres

1 yoctometre

The (SI symbol: ) is a unit of length in the metric system equal to .

1 zeptometre

The (SI symbol: ) is a unit of length in the metric system equal to . To help compare different orders of magnitude, this section lists lengths between 10−21 m and 10−20 m (1 zm and 10 zm).

10 zeptometres

To help compare different orders of magnitude, this section lists lengths between 10−20 m and 10−19 m (10 zm and 100 zm).

100 zeptometres

To help compare different orders of magnitude, this section lists lengths between 10−19 m and 10−18 m (100 zm and 1 am).

1 attometre

The (SI symbol: ) is a unit of length in the metric system equal to . To help compare different orders of magnitude, this section lists lengths between 10−18 m and 10−17 m (1 am and 10 am).

10 attometres

To help compare different orders of magnitude, this section lists lengths between 10−17 m and 10−16 m (10 am and 100 am).

  • 10–100 am – range of the weak force

  • 86 am – charge radius of a Bottom eta meson

100 attometres

To help compare different orders of magnitude, this section lists lengths between 10−16 m and 10−15 m (100 am and 1 fm).

  • 831 am – approximate proton radius

1 femtometre (or 1 fermi)

The (SI symbol: ) is a unit of length in the metric system equal to . In particle physics, this unit is sometimes called a fermi, also with abbreviation "fm". To help compare different orders of magnitude, this section lists lengths between 10−15 metres and 10−14 metres (1 femtometre and 10 fm).

10 femtometres

To help compare different orders of magnitude, this section lists lengths between 10−14 m and 10−13 m (10 fm and 100 fm).

100 femtometres

To help compare different orders of magnitude, this section lists lengths between 10−13 m and 10−12 m (100 fm and 1 pm).

  • 570 fm – typical distance from the atomic nucleus of the two innermost electrons (electrons in the 1s shell) in the uranium atom, the heaviest naturally occurring atom

1 picometre

The (SI symbol: pm) is a unit of length in the metric system equal to (). To help compare different orders of magnitude this section lists lengths between 10−12 and 10−11 m (1 pm and 10 pm).

10 picometres

To help compare different orders of magnitude this section lists lengths between 10−11 and 10−10 m (10 pm and 100 pm).

100 picometres

To help compare different orders of magnitude this section lists lengths between 10−10 and 10−9 m (100pm and 1nm; 1Å and 10Å).

1 nanometre

The (SI symbol: ) is a unit of length in the metric system equal to (). To help compare different orders of magnitude, this section lists lengths between 10−9 and 10−8 m (1nm and 10nm).

10 nanometres

To help compare different orders of magnitude this section lists lengths between 10−8 and 10−7 m (10nm and 100nm).

100 nanometres

To help compare different orders of magnitude, this section lists lengths between 10−7 and 10−6 m (100 nm and 1μm).

  • 100nm – greatest particle size that can fit through a surgical mask

  • 100nm – 90% of particles in wood smoke are smaller than this.

  • 120nm – greatest particle size that can fit through a ULPA filter

  • 120nm – diameter of a human immunodeficiency virus (HIV)

  • 120nm – approximate diameter of SARS-CoV-2

  • 125nm – standard depth of pits on compact discs (width: 500nm, length: 850nm to 3.5μm)

  • 180nm – typical length of the rabies virus

  • 200nm — typical diameter of the chickenpox virus

  • 200nm – typical size of a Mycoplasma bacterium, among the smallest bacteria

  • 300nm – greatest particle size that can fit through a HEPA (high efficiency particulate air) filter (N100 removes up to 99.97% at 300 nm, N95 removes up to 95% at 300 nm)

  • 300–400nm – near ultraviolet wavelength

  • 400 nm – length of the capsid of a Mimivirus, one of the largest and most complex viruses.

  • 400–420nm – wavelength of violet light (see Color and Visible spectrum)

  • 420–440nm – wavelength of indigo light

  • 440–500nm – wavelength of blue light

  • 500–520nm – wavelength of cyan light

  • 520–565nm – wavelength of green light

  • 565–590nm – wavelength of yellow light

  • 590–625nm – wavelength of orange light

  • 625–700nm – wavelength of red light

  • 700 nm–1.4 μm – wavelength of near-infrared radiation

1 micrometre (or 1 micron)

The (SI symbol: ) is a unit of length in the metric system equal to (). To help compare different orders of magnitude, this section lists some items with lengths between 10−6 and 10−5 m (between 1 and 10 micrometres, or μm).

10 micrometres

To help compare different orders of magnitude, this section lists lengths between 10−5 m and 10−4 m (10 μm and 100μm).

  • 10 μm – width of cotton fibre

  • 10 μm – tolerance of the mold used to manufacture a Lego brick

  • 10 μm – transistor width of the Intel 4004, the world's first commercial microprocessor

  • 10 μm – mean longest dimension of a human red blood cell

  • 5–20 μm – dust mite excreta

  • 10.6 μm – wavelength of light emitted by a carbon dioxide laser

  • 15 μm – width of silk fibre

  • 17 μm – minimum width of a strand of human hair

  • 17.6 μm – one twip, a unit of length in typography

  • 10 to 55 μm – width of wool fibre

  • 20 μm — diameter of a cloud droplet

  • 25 μm — diameter of grass pollen

  • 25.4 μm – 1/1,000inch, commonly referred to as 1 mil in the U.S. and 1 thou in the U.K.

  • 30 μm – length of a human skin cell

  • 30.8568 μm – 1 zeptoparsec

  • 50 μm – typical length of Euglena gracilis, a flagellate protist

  • 50 μm – typical length of a human liver cell, an average-sized body cell

  • 50 μm – length of a silt particle

  • 60 μm – length of a human sperm cell

  • 78μm — width of a pixel on the display of the iPhone 4, marketed as Retina Display

  • 70 to 180 μm – thickness of paper

100 micrometres

To help compare different orders of magnitude, this section lists lengths between 10−4 m and 10−3 m (100μm and 1mm). The term myriometre (abbr. mom, equivalent to 100 micrometres; frequently confused with the myriametre, 10 kilometres) is deprecated; the decimal metric prefix myrio- is obsolete and was not included among the prefixes when the International System of Units was introduced in 1960.

  • 100 μm – 1/10 of a millimetre

  • 100 μm – 0.00394inches

  • 100 μm – smallest distance that can be seen with the naked eye

  • 100 μm – average diameter of a strand of human hair

  • 100 μm – thickness of a coat of paint

  • 100 μm – length of a dust particle

  • 120 μm – the geometric mean of the Planck length and the diameter of the observable universe:

  • 120 μm – diameter of a human ovum

  • 139 µm - the size of Dicopomorpha echmepterygis, the smallest insect

  • 170μm – length of the largest mammalian sperm cell (rat)

  • 170 μm – length of the largest sperm cell in nature, belonging to the Drosophila bifurca fruit fly

  • 181 μm – maximum width of a strand of human hair

  • 100–400 μm – length of Demodex mites living in human hair follicles

  • 175–200 μm – typical thickness of a solar cell.

  • 200 μm – typical length of Paramecium caudatum, a ciliate protist

  • 200 μm – nominal width of the smallest commonly available mechanical pencil lead (0.2mm)

  • 250–300 μm – length of a dust mite

  • 340 μm – length of a pixel on a 17-inch monitor with a resolution of 1024×768

  • 500 μm – typical length of Amoeba proteus, an amoeboid protist

  • 500 μm – length of a tardigrade

  • 500 μm – MEMS micro-engine

  • 500 μm – average length of a grain of sand

  • 500 μm – average length of a grain of salt

  • 500 μm – average length of a grain of sugar

  • 560 μm – thickness of the central area of a human cornea

  • 750 μm – diameter of a Thiomargarita namibiensis, which used to be considered the largest bacteria known

  • 760 μm – thickness of an identification card

1 millimetre

The (SI symbol: ) is a unit of length in the metric system equal to (). To help compare different orders of magnitude, this section lists lengths between 10−3 m and 10−2 m (1mm and 1cm).

  • 1.0mm – 1/1,000 of a metre

  • 1.0mm – 0.03937 inches or 5/127 (exactly)

  • 1.0mm – side of a square of area 1 mm²

  • 1.0mm – diameter of a pinhead

  • 1.5mm – average length of a flea

  • 2mm — diameter of an average rain droplet

  • 2.54mm – distance between pins on old dual in-line package (DIP) electronic components

  • 5mm – length of an average red ant

  • 5mm – diameter of an average grain of rice

  • 5.56×45 mm NATO – standard ammunition size

  • 6mm – approximate width of a pencil

  • 7mm – length of a Paedophryne amauensis, the smallest-known vertebrate

  • 7mm – length of a human tooth

  • 7.1mm – length of a sunflower seed

  • 7.62×51 mm NATO – common military ammunition size

  • 8mm – width of old-format home movie film

  • 8mm – length of a Paedocypris progenetica, the smallest-known fish

1 centimetre

The (SI symbol: ) is a unit of length in the metric system equal to (). To help compare different orders of magnitude, this section lists lengths between 10−2 m and 10−1 m (1cm and 1dm).

  • 1cm – 10 millimetres

  • 1cm – 0.39 inches

  • 1cm – edge of a square of area 1 cm2

  • 1cm – edge of a cube of volume 1 mL

  • 1cm – length of a coffee bean

  • 1cm – approximate width of average fingernail

  • 1.2cm – length of a bee

  • 1.2cm – diameter of a die

  • 1.5cm – length of a very large mosquito

  • 1.6cm – length of a Jaragua Sphaero, a very small reptile

  • 1.7cm – length of a Thorius arboreus, the smallest salamander

  • 1.77cm – approximate diameter of a black hole the mass of earth.

  • 2cm – approximate width of an adult human finger

  • 2 cm – upper bound of the length of the largest bacteria, the Thiomargarita magnifica.

  • 2.4cm – diameter of a human eye

  • 2.54cm – 1 inch

  • 3.08568cm – 1 attoparsec

  • 3.4cm – length of a quail egg

  • 3.5cm – width of film commonly used in motion pictures and still photography

  • 3.78cm – amount of distance the Moon moves away from Earth each year

  • 4.3cm – minimum diameter of a golf ball

  • 5cm – usual diameter of a chicken egg

  • 5cm – height of a Etruscan shrew, the smallest-known mammal

  • 5.08cm – 2 inches,

  • 5.5cm – height of a hummingbird, the smallest-known bird

  • 5.5 × 5.5 × 5.5cm – dimensions of a standard 3x3x3 Rubik's cube

  • 6.1cm – average height of an apple

  • 7.3–7.5cm – diameter of a baseball

  • 8.6cm × 5.4cm – dimensions of a standard credit card (also called CR80)

  • 9cm – length of a speckled padloper, the smallest-known turtle

1 decimetre

The (SI symbol: ) is a unit of length in the metric system equal to (). To help compare different orders of magnitude, this section lists lengths between 10 centimetres and 100 centimetres (10−1 metre and 1metre).

Conversions

10 centimetres (abbreviated to 10cm) is equal to:

Wavelengths

Human-defined scales and structures

  • 10cm = 1 dm — length of a kazoo instrument

  • 10.16cm = 1.016 dm – 1 hand used in measuring height of horses (4inches)

  • 12cm = 1.2 dm – diameter of a compact disc (CD) (120mm)

  • 9-12cm = 0.9-1.2dm — average height of a soda can

  • 15cm = 1.5 dm – length of a Bic pen with cap on

  • 20cm = 2 dm — height of a water bottle

  • 22cm = 2.2 dm – diameter of a typical association football (soccer ball)

  • 30cm = 3 dm – typical school-use ruler length (300mm)

  • 30.48cm = 3.048 dm – 1 foot (measure)

  • 60cm = 6 dm – standard depth (front to back) of a domestic kitchen worktop in Europe (600mm)

  • 60cm = 6 dm — diameter of the LAGEOS satellite

  • 90cm = 9 dm – average length of a rapier, a fencing sword

  • 91cm = 9.1 dm — length of a shopping cart

  • 91.44cm = 9.144 dm – one yard (measure)

Nature

  • 10cm = 1 dm – diameter of the human cervix upon entering the second stage of labour

  • 11cm = 1.1 dm – length of an average potato in the U.S.

  • 13cm = 1.3 dm – body length of a Goliath birdeater

  • 18.1cm = 1.81 dm – Maximum overall length of the Hercules beetle, one of the largest beetle species

  • 19cm = 1.9 dm — length of an average male human hand

  • 19cm = 1.9 dm – length of a banana

  • 20cm = 2 dm — diameter of the Syringammina, one of the largest single-celled organisms

  • 20cm = 2 dm - average height of the Venus flytrap

  • 26.3cm = 2.6 dm – length of an average male human foot

  • 29.98cm = 2.998 dm – distance light in vacuum travels in one nanosecond

  • 30cm = 3.0 dm – maximum leg length of a Goliath birdeater

  • 31cm = 3.1 dm – wingspan of largest butterfly species Ornithoptera alexandrae

  • 32cm – length of the Goliath frog, the world's largest frog

  • 46cm = 4.6 dm – length of an average domestic cat

  • 46cm = 4.6 dm – skull length of a Kelenken, a terror bird

  • 50 to 65cm = 5 to 6.5 dm – a coati's tail

  • 66cm = 6.6 dm – length of the longest pine cones (produced by the sugar pine)

  • 80cm = 8 dm - height of a chimpanzee

  • 90cm = 9 dm — length of a capybara, the largest rodent

Astronomical

1 metre

To help compare different orders of magnitude, this section lists lengths between one metre and ten metres. Light, in vacuum, travels 1 metre in , or of a second.

Conversions

1 metre is:

Human-defined scales and structures

  • 1 m – approximate height to the top part of a doorknob on a door

  • 1 m – diameter of a very large beach ball

  • 1 m – height of a typical washing machine

  • 1.29 m – length of the Cross Island Chapel, the smallest church in the world

  • 1.4 m – length of a Peel P50, the world's smallest car

  • 1.4 m – length of a pool noodle

  • 1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4ft 8 in

  • 1.5 m – height of the Lasko pedestal fan

  • 1.8 m – height of an average refrigerator

  • 1.9 m – height of a vending machine

  • 2 m – typical height of an average door

  • 2.5 m – distance from the floor to the ceiling in an average residential house

  • 2.7 m – length of the Starr Bumble Bee II, the smallest plane

  • 2.77–3.44 m – wavelength of the broadcast radio FM band 87–108MHz

  • 2.8 m – height of a telephone booth

  • 3.05 m – the length of an old Mini

  • 6 m – height of an average typical house

  • 8 m – length of the Tsar Bomba, the largest bomb ever detonated

  • 8.38 m – the length of a London Bus (AEC Routemaster)

Sports

Nature

Astronomical

  • 3 to 6 m – approximate diameter of , a meteoroid

  • 4.1 m – diameter of 2008 TC3, a small asteroid that flew into the Earth's atmosphere on 7 October 2008

1 decametre

The (SI symbol: ) is a unit of length in the metric system equal to 10metres (101m). To help compare different orders of magnitude, this section lists lengths between 10 and 100 metres.

Conversions

10 metres (very rarely termed a decametre which is abbreviated as dam) is equal to:

Human-defined scales and structures

Sports

  • 11 metres – approximate width of a doubles tennis court

  • 15 metres – width of a standard FIBA basketball court

  • 15.24 metres – width of an NBA basketball court (50feet)

  • 18.44 metres – distance between the front of the pitcher's rubber and the rear point of home plate on a baseball field (60 feet, 6inches)

  • 20 metres – length of cricket pitch (22 yards)

  • 27.43 metres – distance between bases on a baseball field (90feet)

  • 28 metres – length of a standard FIBA basketball court

  • 28.65 metres – length of an NBA basketball court (94feet)

  • 49 metres – width of an American football field (53 yards)

  • 59.436 metres – width of a Canadian football field (65 yards)

  • 70 metres – typical width of an association football field

  • 91 metres – length of an American football field (100 yards, measured between the goal lines)

Nature

  • 10 metres – average length of human digestive tract

  • 12 metres – height of a standard saguaro cactus

  • 12 metres – moderate length of a whale shark, largest living fish

  • 12 metres – wingspan of a Quetzalcoatlus, a pterosaur

  • 12 metres – length of a Sarcosuchus, the largest crocodile ever

  • 12.8 metres – length of a Titanoboa, the largest snake to have ever lived

  • 13 metres – approximate length of a giant squid and colossal squid, the largest living invertebrates

  • 13 metres – length of a Tyrannosaurus, the most popular dinosaur

  • 14 metres – typical length of a Whale shark, the largest fish today

  • 15 metres – approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt

  • 16 metres – length of a sperm whale, the largest toothed whale

  • 17 metres – length of an average-sized Megalodon, widely considered to be the largest shark to ever roam the waters

  • 18 metres – height of a Sauroposeidon, the tallest-known dinosaur

  • 18 metres – maximum length of Spinosaurus, the largest land-living carnivore ever existed

  • 20 metres – length of a Leedsichthys, the largest-known fish to have lived

  • 21 metres – height of High Force waterfall in England

  • 30.5 metres – length of the lion's mane jellyfish, the largest jellyfish in the world

  • 33 metres – length of a blue whale, the largest animal on earth, living or extinct, in terms of mass

  • 35 metres – length of an Argentinosaurus, the second-longest dinosaur

  • 39 metres – length of a Supersaurus, the longest-known dinosaur and longest vertebrate

  • 40 metres – supposed length of Maraapunisaurus

  • 44 metres – potential length of Bruhathkayosaurus in studies of 2023

  • 52 metres – height of Niagara Falls

  • 55 metres – length of a bootlace worm, the longest-known animal

  • 58 metres – possible length of an Amphicoelias

  • 66 metres – highest possible sea level rise due to a complete melting of all ice on Earth

  • 83 metres – height of a western hemlock

  • 84 metres – height of General Sherman, the largest tree by volume in the world

Astronomical

  • 30.8568 metres – 1 femtoparsec

  • 11 metres – diameter of , a rapidly spinning asteroid

1 hectometre

The (SI symbol: ) is a unit of length in the metric system equal to 100metres (102m). To compare different orders of magnitude this section lists lengths between 100 metres and 1,000 metres (1 kilometre).

Conversions

100 metres (sometimes termed a hectometre) is equal to:

Human-defined scales and structures

Sports

  • 100 metres – the distance a very fast human can run in about 10 seconds

  • 100.584 metres – length of a Canadian football field between the goal lines (110 yards)

  • 91.5 metres – 137 metres – length of a soccer field

  • 105 metres – length of football pitch (UEFA stadium categories 3 and 4)

  • 105 metres – length of a typical football field

  • 109.73 metres – total length of an American football field (120 yards, including the end zones)

  • 110 to 150 metres – the width of an Australian football field

  • 135 to 185 metres – the length of an Australian football field

  • 137.16 metres – total length of a Canadian football field, including the end zones (150 yards)

Nature

  • 115.5 metres – height of the world's tallest tree in 2007, the Hyperion sequoia

  • 310 metres – maximum depth of Lake Geneva

  • 340 metres – distance sound travels in air at sea level in one second; see Speed of sound

  • 947 metres – height of the Tugela Falls, the highest waterfall in Africa

  • 979 metres – height of the Angel Falls in Venezuela, the world's highest free-falling waterfall

Astronomical

1 kilometre

The (SI symbol: ) is a unit of length in the metric system equal to metres (103m). To help compare different orders of magnitude, this section lists lengths between 1kilometre and 10kilometres (103 and 104 metres).

Conversions

1 kilometre (unit symbol km) is equal to:

Human-defined scales and structures

Nature

  • 1.5km – distance sound travels in water in one second

Geographical

Astronomical

10 kilometres (1 myriametre)

To help compare different orders of magnitude, this section lists lengths between 10 and 100 kilometres (104 to 105 metres). The myriametre (sometimes also spelled myriometre; 10,000 metres) is a deprecated unit name; the decimal metric prefix myria- (sometimes also written as myrio-) is obsolete and was not included among the prefixes when the International System of Units was introduced in 1960.

Conversions

10 kilometres is equal to:

1 mil (the Scandinavian mile), now standardized as 10km:

  • 1 mil, the unit of measure commonly used in Norway and Sweden used to be 11,295m in Norway and 10,688m in Sweden.

  • farsang, unit of measure commonly used in Iran and Turkey

Sports

Human-defined scales and structures

Geographical

Astronomical

100 kilometres

A length of 100 kilometres (about 62 miles), as a rough amount, is relatively common in measurements on Earth and for some astronomical objects. It is the altitude at which the FAI defines spaceflight to begin.

To help compare orders of magnitude, this section lists lengths between 100 and 1,000 kilometres (105 and 106 metres).

Conversions

A distance of 100 kilometres is approximately 62 miles (or exactly).

Human-defined scales and structures

Geographical

Astronomical

1 megametre

The (SI symbol: ) is a unit of length in the metric system equal to metres (106m). To help compare different orders of magnitude, this section lists lengths starting at 106 m (1 Mm or 1,000 km).

Conversions

1 megametre is equal to:

  • 1000 km

  • (one million metres)

  • approximately 621.37 miles

Human-defined scales and structures

Sports

Several endurance auto races are, or were, run for 1,000km:

Geographical

Astronomical

10 megametres

To help compare different orders of magnitude, this section lists lengths starting at 107 metres (10 megametres or 10,000 kilometres).

Conversions

10 megametres (10 Mm) is

Human-defined scales and structures

Geographical

Astronomical

100 megametres

To help compare different orders of magnitude, this section lists lengths starting at 108 metres (100 megametres or 100,000 kilometres or 62,150 miles).

1 gigametre

The (SI symbol: ) is a unit of length in the metric system equal to metres (109m). To help compare different distances this section lists lengths starting at 109 metres (1 gigametre (Gm) or 1 billion metres).

10 gigametres

To help compare different distances this section lists lengths starting at 1010 metres (10 gigametress (Gm) or 10 million kilometres, or 0.07 astronomical units).

100 gigametres

To help compare distances at different orders of magnitude this section lists lengths starting at 1011 metres (100 gigametre or 100 million kilometres or 0.7 astronomical units).

  • 103 Gm (0.69 au) – diameter of Rigel

  • 109 Gm (0.7 au) – distance between Venus and the Sun

  • 149.6 Gm (93.0 million mi; 1.0 au) – average distance between the Earth and the Sun – the original definition of the astronomical unit

  • 163 Gm (1.09 au) – diameter of Deneb, a blue supergiant

  • 228 Gm (1.5 au) – distance between Mars and the Sun

  • 255 Gm (1.7 au) – diameter of Enif, a small red supergiant star in the constellation Pegasus

  • 511 Gm (3.4 au) – average diameter of Mira, a pulsating red giant and the progenitor of the Mira variables. It is an asymptotic giant branch star.

  • 570 Gm (3.8 au) – length of the tail of Comet Hyakutake measured by Ulysses; the actual value could be much higher

  • 590 Gm (3.9 au) – diameter of the Pistol Star, a blue hypergiant star

  • 591 Gm (4.0 au) – minimum distance between the Earth and Jupiter

  • 780 Gm (5.2 au) – average distance between Jupiter and the Sun

  • 785 Gm (5.25 au) – diameter of Rho Cassiopeiae, a rare yellow hypergiant star

  • 947 Gm (6.4 au) – diameter of Antares A

  • 965 Gm (6.4 au) – maximum distance between the Earth and Jupiter

1 terametre

The (SI symbol: ) is a unit of length in the metric system equal to metres (1012m). To help compare different distances, this section lists lengths starting at 1012 m (1 Tm or 1 billion km or 6.7 astronomical units).

  • ≈1 Tm – 6.7 au – diameter of the red supergiant Betelgeuse based on multiple angular diameter estimates

  • 1.032 Tm – 6.9 au – diameter of the blue hypergiant Eta Carinae (at optical depth 2/3)

  • 1.079 Tm – 7.2 au – one light-hour

  • 1.4 Tm – 9.5 au – average distance between Saturn and the Sun

  • 1.47 Tm – 9.9 au – diameter of HR 5171 A, a yellow hypergiant star

  • 1.5 Tm – 10 au – estimated diameter of VV Cephei A, a red hypergiant with a blue dwarf companion.

  • 1.75 Tm – 11.7 au – estimated diameter of Mu Cephei, a red supergiant (possibly hypergiant) among the largest-known stars.

  • 2 Tm – 13.2 au – estimated diameter of VY Canis Majoris, a red hypergiant that is among the largest-known stars

  • 2.1 Tm – 14.2 au – estimated diameter of RSGC1-FO1, the largest star in the Galaxy.

  • 2.143 Tm – 14.3 au – estimated diameter of WOH G64, possibly the largest star known in the Large Magellanic Cloud.

  • 2.9 Tm – 19.4 au – average distance between Uranus and the Sun

  • 4.4 Tm – 29.4 au – perihelion distance of Pluto

  • 4.5 Tm – 30.1 au – average distance between Neptune and the Sun

  • 4.5 Tm – 30.1 au – inner radius of the Kuiper belt

  • 5.7 Tm – 38.1 au – perihelion distance of Eris

  • 6.0 Tm – 40.5 au – distance from Earth at which the Pale Blue Dot photograph was taken.

  • 7.3 Tm – 48.8 au – aphelion distance of Pluto

  • 7.5 Tm – 50.1 au – outer boundary of the Kuiper Belt

10 terametres

To help compare different distances this section lists lengths starting at 1013 m (10 Tm or 10 billion km or 67 astronomical units).

  • 10 Tm – 67 AU – diameter of a hypothetical quasi-star

  • 11.1 Tm – 74.2 AU – distance that Voyager 1 began detecting returning particles from termination shock

  • 11.4 Tm – 76.2 AU – perihelion distance of 90377 Sedna

  • 12.1 Tm – 70 to 90 AU – distance to termination shock (Voyager 1 crossed at 94 AU)

  • 12.9 Tm – 86.3 AU – distance to 90377 Sedna in March 2014

  • 13.2 Tm – 88.6 AU – distance to Pioneer 11 in March 2014

  • 14.1 Tm – 94.3 AU – estimated radius of the Solar System

  • 14.4 Tm – 96.4 AU – distance to Eris in March 2014 (now near its aphelion)

  • 15.1 Tm – 101 AU – distance to heliosheath

  • 16.5 Tm – 111 AU – distance to Pioneer 10 as of March 2014

  • 16.6 Tm – 111.2 AU – distance to Voyager 2 as of May 2016

  • 18 Tm – 123.5 AU – distance between the Sun to the farthest dwarf planet in the Solar System, the Farout 2018 VG18

  • 19.5 Tm – 132.7 AU – distance between the Sun to one of the farthest known objects in the solar system, 2018 AG37 (FarFarOut)

  • 20.0 Tm – 135 AU – distance to Voyager 1 as of May 2016

  • 20.6 Tm – 138 AU – distance to Voyager 1 as of late February 2017

  • 21 Tm – 140 AU – distance to Voyager 2 as of August 2025

  • 21.1 Tm – 141 AU – distance to Voyager 1 as of November 2017

  • 21.4 Tm – 142.8 AU – distance to Voyager 2 as of February 2026

  • 25.1 Tm – 168 AU – distance to Voyager 1 as of August 2025

  • 25.7 Tm – 171.7 AU – distance to Voyager 1 as of February 2026

  • 25.9 Tm – 173 AU – one light-day

  • 30.8568 Tm – 206.3 AU – 1 milliparsec

  • 55.7 Tm – 371 AU – aphelion distance of the comet Hale-Bopp

100 terametres

To help compare different distances this section lists lengths starting at 1014 m (100 Tm or 100 billion km or 670 astronomical units).

1 petametre

The (SI symbol: ) is a unit of length in the metric system equal to 1015metres. To help compare different distances this section lists lengths starting at 1015 m (1 Pm or 1 trillion km or 6685 astronomical units (AU) or 0.11 light-years).

  • 1.0 Pm = 0.105702341 light-years

  • 1.9 Pm ± 0.5 Pm = 12,000 AU = 0.2 light-year radius of Cat's Eye Nebula's inner core

  • 3.08568 Pm = 20,626 AU = 1 deciparsec

  • 4.7 Pm = 30,000 AU = half-light-year diameter of Bok globule Barnard 68

  • 7.5 Pm – 50,000 AU – possible outer boundary of Oort cloud (other estimates are 75,000 to 125,000 or even 189,000 AU (1.18, 2, and 3 light-years, respectively))

  • 9.5 Pm – 63,241.1 AU – one light-year, the distance light travels in one year

  • 9.9 Pm – 66,000 AU – aphelion distance of the C/1999 F1 (Catalina)

10 petametres

To help compare different distances this section lists lengths starting at 1016 m (10 Pm or 66,800 AU, 1.06 light-years).

  • 15 Pm – 1.59 light-years – possible outer radius of Oort cloud

  • 20 Pm – 2.11 light-years – maximum extent of influence of the Sun's gravitational field

  • 30.9 Pm – 3.26 light-years – 1 parsec

  • 39.9 Pm – 4.22 light-years – distance to Proxima Centauri (nearest star to Sun)

  • 81.3 Pm – 8.59 light-years – distance to Sirius

  • 94.6 Pm – 1 light-decade

100 petametres

To help compare different distances this section lists lengths between 1017 m (100 Pm or 11 light-years) and 1018 m (106 light-years).

  • 110 Pm – 12 light-years – Distance to Tau Ceti

  • 230 Pm – 24 light-years – diameter of the Orion Nebula

  • 240 Pm – 25 light-years – Distance to Vega

  • 260 Pm – 27 light-years – Distance to Chara, a star approximately as bright as the Sun. Its faintness gives an idea how the Sun would appear when viewed from this distance.

  • 308.568 Tm – 32.6 light-years – 1 dekaparsec

  • 350 Pm – 37 light-years – distance to Arcturus

  • 373.1 Pm – 39.44 light-years – distance to TRAPPIST-1, a star recently discovered to have 7 planets around it

  • 400 Pm – 42 light-years – distance to Capella

  • 620 Pm – 65 light-years – distance to Aldebaran

  • 750 Pm – 79.36 light-years – distance to Regulus

  • 900 Pm – 92.73 light-years – distance to Algol

  • 946 Pm – 1 light-century

1 exametre

The (SI symbol: ) is a unit of length in the metric system equal to 1018 metres. To help compare different distances this section lists lengths between 1018m (1Em or 105.7 light-years) and 1019m (10Em or 1,057 light-years).

  • 1.2 Em – 129 light-years – diameter of Messier 13 (a typical globular cluster)

  • 1.6 Em – 172 ± 12.5 light-years – diameter of Omega Centauri (one of the largest-known globular clusters, perhaps containing over a million stars)

  • 3.08568 Em – 326.1 light-years – 1 hectoparsec

  • 3.1 Em – 310 light-years – distance to Canopus according to Hipparcos

  • 3.9 Em – 410 light-years – distance to Betelgeuse according to Hipparcos

  • 6.2 Em – 650 light-years – distance to the Helix Nebula, located in the constellation Aquarius

  • 8.2 Em – 860 light-years – distance to Rigel according to Hipparcos

  • 9.4 Em — 1 light-millennium – 1000 light-years

10 exametres

To help compare different orders of magnitude, this section lists distances starting at 10 Em (1019 m or 1,100 light-years).

100 exametres

To help compare different orders of magnitude, this section lists distances starting at 100 Em (1020 m or 11,000 light-years).

1 zettametre

The (SI symbol: ) is a unit of length in the metric system equal to 1021 metres. To help compare different orders of magnitude, this section lists distances starting at 1Zm (1021m or 110,000 light-years).

10 zettametres

To help compare different orders of magnitude, this section lists distances starting at 10 Zm (1022 m or 1.1 million light-years).

100 zettametres

To help compare different orders of magnitude, this section lists distances starting at 100 Zm (1023 m or 11 million light-years).

1 yottametre

The (SI symbol: ) is a unit of length in the metric system equal to 1024metres.

To help compare different orders of magnitude, this section lists distances starting at 1 Ym (1024 m or 105.702 million light-years).

10 yottametres

To help compare different orders of magnitude, this section lists distances starting at 10 Ym (1025 m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used.

100 yottametres

To help compare different orders of magnitude, this section lists distances starting at 100 Ym (1026 m or 11 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

1 ronnametre

The (SI symbol: ) is a unit of length in the metric system equal to 1027metres.

To help compare different orders of magnitude, this section lists distances starting at 1 Rm (1027 m or 105.7 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used.

  • >1 Rm – >105.7 billion light-years – size of universe beyond the cosmic light horizon, depending on its curvature; if the curvature is zero (i.e. the universe is spatially flat), the value can be infinite (see Shape of the universe) as previously mentioned.

  • 2.764 Rm - 292.2 billion light-years – circumference of the observable universe, as it is in the shape of a sphere.

  • 221.617 Rm - 23.425 trillion light-years - circumference of the observable universe, as it is in the shape of a hypersphere.

1 quettametre

The (SI symbol: ) is a unit of length in the metric system equal to 1030metres.

Upper limits

See also

Notes

References