List of examples of lengths



This is a list of examples of lengths, in metres in order to give an understanding of lengths.

Shorter than 1 ym

 * $1.62$ metres = $1.62$ qm = the Planck length
 * $1$ metres = 1 qm = 1 quectometre, the smallest named subdivision of the metre in the SI base unit of length.
 * $1$ metres = 1 rm = 1 rontometre = $1,000$ quectometres

1 ym to 1 zm

 * $1$ metres = 1 ym = 1 yoctometre = $1,000$ rontometres
 * $1$ metres = 10 ym
 * $2$ metres = 20 ym, the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines
 * $6.3 cm2$ metres = 100 ym

1 zm to 1 am

 * $2 m$ metres = 1 zm = 1 zeptometre = $1$ yoctometres
 * $1$ metres = radius of effective cross section for a 20 GeV neutrino scattering off a nucleon
 * $1,000$ metres = radius of effective cross section for a 250 GeV neutrino scattering off a nucleon
 * $2$ metres = 10 zm
 * $1 m2$ metres = 100 zm
 * 310 zm — de Broglie wavelength of protons at the Large Hadron Collider (4 TeV as of 2012)

1 am to 1 fm

 * $2 m$ metres = 1 am = 1 attometre = $1.5 m2$ zeptometres
 * 1 am — sensitivity of the LIGO detector for gravitational waves
 * $7 m$ metres = 10 am
 * $7$ metres = 100 am
 * 0.85 fm — approximate proton radius

1 fm to 1 pm

 * $1$ metres = 1 fm = 1 femtometre = $1$ attometres
 * 1.5 fm — diameter of the Scattering Cross Section of an 11 MeV proton with a target proton
 * $1$ — classical electron radius
 * 7 fm - the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees
 * $1,000$ metres = 10 fm
 * $1$ metres = 100 fm
 * $1$ metres = 1 pm = 1 picometre = $1$ femtometres

1 picometre
Lengths between 10−12 and 10−11 m (1 and 10 pm).


 * 1 pm = 1 picometre = $1,000$ femtometres
 * 1 pm = distance between atomic nuclei in a white dwarf star
 * 2.4 pm — The Compton wavelength of the electron.
 * 5 pm — shorter X-ray wavelengths (approx.)

10 picometres
Lengths between 10−11 and 10−10 m (10 pm and 100 pm).
 * 25 pm — empirical radius of hydrogen atom
 * 28 pm — covalent radius of helium atom
 * 31 pm — covalent radius of hydrogen atom
 * 31 pm — calculated radius of helium atom
 * ~50 pm — best resolution of a high-resolution transmission electron microscope
 * 53 pm — calculated radius of hydrogen atom

100 picometres
Lengths between 10−10 and 10−9 m (100 pm and 1 nm).


 * 100 pm — 1 angstrom
 * 100 pm — covalent radius of sulfur atom
 * 120 pm — van der Waals radius of a neutral hydrogen atom
 * 126 pm — covalent radius of ruthenium atom
 * 135 pm — covalent radius of technetium atom
 * 153 pm — covalent radius of silver atom
 * 154 pm — mode length of (C-C) covalent bond
 * 155 pm — covalent radius of zirconium atom
 * 175 pm — covalent radius of thulium atom
 * 200 pm — highest resolution of a typical electron microscope
 * 225 pm — covalent radius of caesium atom
 * 340 pm — thickness of single layer graphene
 * 356.68 pm — width of diamond cell (unit cell)
 * 403 pm — width of lithium fluoride cell
 * 500 pm — width of α helix protein
 * 560 pm — width of sodium chloride cell
 * 700 pm — width of glucose molecule
 * 780 pm — mean width of quartz cell
 * 820 pm — mean width of ice cell
 * 900 pm — mean width of coesite cell
 * 900 pm — width of sucrose molecule

10 nanometres 1x10−9m
To help compare different orders of magnitude this page lists lengths between 10−8 and 10−7 m (10 and 100 nm).


 * 10 nm = 10 nanometres = 10−8 metres
 * 10 nm — lower size of tobacco smoke
 * 10 nm Shortest extreme ultraviolet wavelength or longest X-ray wavelength
 * 11 nm — the average half-pitch of a memory cell speculated to be manufactured in 2015.
 * 16 nm — technology is projected to be reached by semiconductor companies in the 2013 timeframe
 * 18 nm — diameter of tobacco mosaic virus
 * 20 nm — width of bacterial flagellum
 * 20 nm to 80 nm — thickness of cell wall in Gram-positive bacteria
 * 22 nm — Smallest feature size of production microprocessors in September 2009
 * 22 nm — the average half-pitch of a memory cell expected to be manufactured at around the 2011–2011 time frame.
 * 30 nm — lower size of cooking oil smoke
 * 32 nm — the average half-pitch of a memory cell manufactured at around the 2009–2010 time frame.
 * 45 nm — the average half-pitch of a memory cell manufactured at around the 2007–2008 time frame.
 * 50 nm — upper size for airborne virus particles
 * 50 nm — flying height of the head of a hard disk
 * 65 nm — the average half-pitch of a memory cell manufactured at around the 2005–2006 time frame.
 * 90 nm — the average half-pitch of a memory cell manufactured at around the 2002–2003 time frame.
 * (ranges from 7 to 3000 nanometres)

100 nanometres
Lengths between 10−7 and 10−6 m (100 nm and 1 μm).


 * 100 nm — greatest particle size that can fit through a surgical mask
 * 120 nm — diameter of a human immunodeficiency virus (HIV)
 * 125 nm — standard depth of pits on compact discs (width: 500 nm, length: 850 nm to 3.5 μm)
 * 180 nm — typical length of the rabies virus
 * 200 nm — typical size of a Mycoplasma bacterium, among the smallest bacteria
 * 300-400 nm — near ultraviolet wavelength
 * 400–420 nm — wavelength of violet light
 * 420–440 nm — wavelength of indigo light
 * 440–500 nm — wavelength of blue light
 * 500–520 nm — wavelength of cyan light
 * 520–565 nm — wavelength of green light
 * 565–590 nm — wavelength of yellow light
 * 590–625 nm — wavelength of orange light
 * 625–700 nm — wavelength of red light
 * 700–1400 nm — wavelength of near-infrared radiation
 * 590–625 nm — wavelength of orange light
 * 625–700 nm — wavelength of red light
 * 700–1400 nm — wavelength of near-infrared radiation

1 micrometre
To help compare different orders of magnitude this page lists some items with lengths between 10−6 and 10−5 m (between 1 and 10 micrometres, or μm).


 * ~0.7–300 μm — Wavelength of infrared radiation
 * 1 μm — the side of square of area 10−12 m2
 * 1 μm — edge of cube of volume 10−18 m3 (one femtolitre)
 * 1–10 μm — diameter of a typical bacterium
 * 1.55 μm — wavelength of light used in optical fibre
 * 3–4 μm — size of a typical yeast cell
 * 5 μm — length of a typical human spermatozoon's head
 * 6 μm — anthrax spore
 * 7 μm — diameter of the nucleus of a typical eukaryotic cell
 * about 7 μm — diameter of human red blood cells
 * 3–8 μm — width of strand of spider web silk
 * 8 μm — width of a chloroplast
 * 9 μm — thickness of the tape in a 120-minute compact cassette.
 * about 10 μm — size of a fog, mist or cloud water droplet

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


 * 10 μm — width of cotton fibre
 * 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
 * 16 μm — diameter of a micromirror in a typical Digital micromirror device
 * 17 μm — length of a tobacco mosaic virus
 * 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
 * 25.4 μm — 1/1000 inch, commonly referred to as 1 mil in the U.S. and 1 thou in the UK
 * 50 μm — typical length of Euglena gracilis, a flagellate protist
 * 50 μm — typical length of a human liver cell, an average-sized body cell
 * 78 μm — width of a pixel on the display of the iPhone 4, marketed as Retina Display
 * 90 μm — paper thickness in average
 * 1 myriometre, Distances shorter than 100 μm
 * 1 myriometre, Distances shorter than 100 μm

100 micrometres
To help compare different orders of magnitude, this page lists lengths between 10−4 and 10−3 m (100 μm and 1 mm).


 * 100 μm – 1/10 of a millimetre
 * 100 μm – 0.00394 inches
 * 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 – diameter of a human ovum
 * 170 μm – length of the largest mammalian sperm cell (rat)
 * 181 μm – maximum width of a strand of human hair
 * 100–400 μm – length of Demodex mites living in human hair follicles
 * 200 μm – typical length of Paramecium caudatum, a ciliate protist
 * 250–300 μm – length of a dust mite
 * 340 μm – length of a single pixel on a 17-inch monitor with a resolution of 1024×768
 * 500 μm – typical length of Amoeba proteus, an amoeboid protist
 * 560 μm - thickness of the central area of a human cornea
 * 760 μm – thickness of a credit card
 * 760 μm – thickness of a credit card

1 millimeter
To help compare different orders of magnitude this page lists lengths between 10−3 and 10−2 m (1 mm and 1 cm).


 * 1.0 mm — $2.818 fm$ of a metre
 * 1.0 mm — $1$ inches or $1$ (exactly)
 * 1.0 mm — side of square of area 1 mm2
 * 1.0 mm — diameter of a pinhead
 * 1.5 mm — length of average flea
 * 2.54 mm — distance between pins on old DIP (dual-inline-package) electronic components
 * 5 mm — length of average red ant
 * 5.56×45mm NATO — standard ammunition size
 * 7.62×51mm NATO — common military ammunition size

1 centimeter
Lengths between 10−2 and 10−1 m (1 and 10 cm).


 * 1 cm — 10 millimetres
 * 1 cm — 0.39 inches
 * 1 cm — edge of square of area 1 cm2
 * 1 cm — edge of cube of volume 1 ml
 * 1 cm — approximate width of average fingernail
 * 1.5 cm — length of a very large mosquito
 * 2 cm — approximate width of an adult human finger
 * 2.54 cm — 1 inch
 * 3.1 cm — 1 attoparsec (10−18 parsecs)
 * 3.5 cm — width of film commonly used in motion pictures and still photography
 * 4.3 cm — minimum diameter of a golf ball
 * 7.3-7.5 cm — diameter of a baseball
 * 8.6 cm × 5.4 cm — dimensions of a typical credit card

1 decimetre
Lengths between 10 and 100 centimetres (10−1 and 1 metre).

Conversions
10 centimetres (abbreviated to 10 cm) is equal to
 * 1 decimetre (dm), a term not in common use
 * 100 millimetres
 * 3.9 inches
 * A side of a square of area 0.01 m2
 * The edge of a cube with a volume of $1$ (one litre)

Wavelengths

 * 10 cm = 1.0 dm – wavelength of the highest UHF radio frequency, 3 GHz
 * 12 cm = 1.2 dm – wavelength of the 2.45 GHz ISM radio band
 * 21 cm = 2.1 dm – wavelength of the 1.4 GHz hydrogen emission line, a hyperfine transition of the hydrogen atom
 * 100 cm = 10 dm – wavelength of the lowest UHF radio frequency, 300 MHz

Human-defined scales and structures

 * 10.16 cm = 1.016 dm — 1 hand used in measuring height of horses (4 inches)
 * 12 cm = 1.2 dm — diameter of a Compact Disc (CD) (= 120 mm)
 * 15 cm = 1.5 dm — length of a Bic pen with cap on
 * 22 cm = 2.2 dm — diameter of a typical soccer ball
 * 30.48 cm = 3.048 dm — 1 foot
 * 30 cm = 3 dm — typical school-use ruler length (= 300 mm)
 * 60 cm = 6 dm — standard depth (front to back) of a domestic kitchen worktop in Europe (= 600 mm)
 * 90 cm = 9 dm — average length of a rapier, a fencing sword
 * 91.44 cm = 9.144 dm — one yard
 * Cigarettes 100 mm (4 in) in length

Nature

 * 29.98 cm = distance light travels in one nanosecond
 * 56 cm = 5.6 dm — the length of the average erect horse pеnis
 * 66 cm — length of the longest pine cones (produced by the sugar pine )
 * 29.98 cm = distance light travels in one nanosecond
 * 56 cm = 5.6 dm — the length of the average erect horse pеnis
 * 66 cm — length of the longest pine cones (produced by the sugar pine )
 * 66 cm — length of the longest pine cones (produced by the sugar pine )
 * 66 cm — length of the longest pine cones (produced by the sugar pine )

Longer

 * 1) 1 metre
 * 2) 1 decametre
 * 3) 1 hectometre
 * 4) 1 kilometre
 * 5) 1 myriametre
 * 6) 100 kilometres
 * 7) 1 megametre
 * 8) 10 megametres
 * 9) 100 megametres

1 gigametre
Lengths starting at 109 metres (1 gigametre (Gm) or 1 million kilometres).

Distances shorter than 109 metres
 * 1.4 Gm &mdash; Diameter of Sun
 * 1.5 Gm &mdash; (proposed) Expected orbit from Earth of the James Webb Space Telescope
 * 2.19 Gm &mdash; Closest approach of Comet Lexell to Earth, happened on 1 July 1770; closest comet approach on record
 * 3 Gm &mdash; Total length of "wiring" in the human brain.
 * 4.2 Gm &mdash; Diameter of Algol B
 * 5.0 Gm &mdash; Closest approach of Comet Halley to Earth, happened on 10 April 837
 * 5.0 Gm &mdash; (proposed) Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna (LISA) planned to start observations in or around 2015.
 * 7.9 Gm &mdash; Diameter of Gamma Orionis
 * 9.0 Gm &mdash; Estimated diameter of the event horizon of Sagittarius A*, the supermassive black hole in the center of the Milky Way galaxy

Longer

 * 1) 10 gigametres
 * 2) 100 gigametres
 * 3) 1 terametre
 * 4) 10 terametres
 * 5) 100 terametres
 * 6) 1 light year
 * 7) 1 petametre
 * 8) 10 petametres
 * 9) 100 petametres
 * 10) 1 exametre
 * 11) 10 exametres
 * 12) 100 exametres
 * 13) 1 zettametre
 * 14) 10 zettametres
 * 15) 100 zettametres
 * 16) 1 yottametre
 * 17) 10 yottametres
 * 18) 100 yottametres
 * 19) 1 ronnametre
 * 20) 10 ronnametres
 * 21) 100 ronnametres
 * 22) 1 quettametre
 * 23) 10 quettametres
 * 24) 100 quettametres