Orders of magnitude (length)

To help compare different orders of magnitude, the following list describes various lengths between 1.6 \times 10^{-35} metres and 10^{10^{10^{122}}}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 ==

• 10 rm – the length of one side of a square whose area is one shed, a unit of target cross section used in nuclear physics == 1 yoctometre ==

The ' (SI symbol: ') is a unit of length in the metric system equal to . • 2 ym – the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines. ==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). • 2 zm – the upper bound for the width of a cosmic string in string theory. • 2 zm – radius of effective cross section for a 20 GeV neutrino scattering off a nucleon • 7 zm – radius of effective cross section for a 250 GeV neutrino scattering off a nucleon ==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). • 177 zm – de Broglie wavelength of protons at the Large Hadron Collider (7 TeV as of 2010) ==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). • 1 am – sensitivity of the LIGO detector for gravitational waves • 1 am – upper limit for the size of quarks and electrons ==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 (unit)|, 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). • 1 fm – diameter of a neutron, approximate range-limit of the color force carried between quarks by gluons • 2.81794 fm – classical electron radius • 3 fm – approximate range-limit of the nuclear binding force mediated by mesons • 7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees ==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). • 1.75 to 15 fm – diameter range of the atomic nucleus • 10 fm – the length of one side of a square whose area is one barn (10−28 m2), a unit of target cross section used in nuclear physics • 30.8568 fm – 1 quectoparsec (10−30 parsecs) ==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). • 1 pm – distance between atomic nuclei in a white dwarf • 1 pm – reference value of particle displacement in acoustics • 2.4 pm – the Compton wavelength of an electron • 5 pm – shorter X-ray wavelengths (approx.) ==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). • 25 pm – approximate radius of a helium atom, the smallest neutral atom • 30.8568 pm – 1 rontoparsec • 50 pm – Bohr radius: approximate radius of a hydrogen atom • ~50 pm – best resolution of a high-resolution transmission electron microscope • 60 pm – radius of a carbon atom • 93 pm – length of a diatomic carbon molecule • 96 pm – H–O bond length in a water molecule ==100 picometres==

To help compare different orders of magnitude this section lists lengths between 10−10 and 10−9 m (100 pm and 1 nm; 1 Å and 10 Å). • 100 pm – 1 ångström • 100 pm – covalent radius of sulfur atom • 120 pm – van der Waals radius of a neutral hydrogen atom • 120 pm – radius of a gold atom • 126 pm – covalent radius of ruthenium atom • 135 pm – covalent radius of technetium atom • 150 pm – length of a typical covalent bond (C–C) • 153 pm – covalent radius of silver atom • 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 • 280 pm – average size of the water molecule • 298 pm – radius of a caesium atom, calculated to be the largest atomic radius • 340 pm – thickness of single layer graphene • 356.68 pm – width of diamond unit cell • 403 pm – width of lithium fluoride unit cell • 500 pm – width of protein α helix • 543 pm – silicon lattice spacing • 560 pm – width of sodium chloride unit cell • 700 pm – width of glucose molecule • 700 pm – diameter of a buckyball • 780 pm – mean width of quartz unit cell • 820 pm – mean width of ice unit cell • 900 pm – mean width of coesite unit cell ==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 (1 nm and 10 nm). • 1 nm – diameter of a carbon nanotube • 1 nm – roughly the length of a sucrose molecule, calculated by Albert Einstein • 2.3 nm – length of a phospholipid • 2.3 nm – smallest gate oxide thickness in microprocessors • 3 nm – width of a DNA helix • 3 nm – flying height of the head of a hard disk • 3 nm – the average half-pitch of a memory cell manufactured circa 2022 • 3.4 nm – length of a DNA turn (10 bp) • 3.8 nm – size of an albumin molecule • 5 nm – size of the gate length of a 16 nm processor • 5 nm – the average half-pitch of a memory cell manufactured circa 2019–2020 • 6 nm – length of a phospholipid bilayer • 6–10 nm – thickness of cell membrane • 6.8 nm – width of a hemoglobin molecule • 7 nm – diameter of actin filaments • 7 nm – the average half-pitch of a memory cell manufactured circa 2018 • 10 nm – thickness of cell wall in Gram-negative bacteria ==10 nanometres==

is about 10 times that of the image. To help compare different orders of magnitude this section lists lengths between 10−8 and 10−7 m (10 nm and 100 nm). • 10 nm – shortest extreme ultraviolet wavelength or longest X-ray wavelength • 10 nm – the average length of a nanowire • 10 nm – lower size of tobacco smoke • 10 nm – the average half-pitch of a memory cell manufactured circa 2016 –2017 • 13 nm – the length of the wavelength that is used for EUV lithography • 14 nm – length of a porcine circovirus • 14 nm – the average half-pitch of a memory cell manufactured circa 2013 • 15 nm – length of an antibody • 18 nm – diameter of tobacco mosaic virus • 20 nm – length of a nanobe, could be one of the smallest forms of life • 20–80 nm – thickness of cell wall in Gram-positive bacteria • 20 nm – thickness of bacterial flagellum • 22 nm – the average half-pitch of a memory cell manufactured circa 2011–2012 • 22 nm – smallest feature size of production microprocessors in September 2009 • 25 nm – diameter of a microtubule • 30 nm – lower size of cooking oil smoke • 30.8568 nm – 1 yoctoparsec • 32 nm – the average half-pitch of a memory cell manufactured circa 2009–2010 • 40 nm – extreme ultraviolet wavelength • 45 nm – the average half-pitch of a memory cell manufactured circa 2007–2008 • 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 circa 2005–2006 • 58 nm – height of a T7 bacteriophage • 90 nm – human immunodeficiency virus (HIV) (generally, viruses range in size from 20 nm to 450 nm) • 90 nm – the average half-pitch of a memory cell manufactured circa 2002–2003 • 100 nm – length of a mesoporous silica nanoparticle ==100 nanometres==

is about 10 times that of the image. To help compare different orders of magnitude, this section lists 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 • 100 nm – 90% of particles in wood smoke are smaller than this. • 120 nm – greatest particle size that can fit through a ULPA filter • 120 nm – diameter of a human immunodeficiency virus (HIV) • 120 nm – approximate diameter of SARS-CoV-2 • 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 diameter of the chickenpox virus • 200 nm – typical size of a Mycoplasma bacterium, among the smallest bacteria • 300 nm – 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) • 300–400 nm – near ultraviolet wavelength • 400 nm – length of the capsid of a Mimivirus, one of the largest and most complex viruses. • 400–420 nm – wavelength of violet light (see Color and Visible spectrum) • 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 nm–1.4 μm – wavelength of near-infrared radiation ==1 micrometre (or 1 micron)==