Hubbry Logo
Orders of magnitude (mass)Orders of magnitude (mass)Main
Open search
Orders of magnitude (mass)
Community hub
Orders of magnitude (mass)
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Orders of magnitude (mass)
Orders of magnitude (mass)
Orders of magnitude (mass)
View on Wikipedia
from Wikipedia

To help compare different orders of magnitude, the following lists describe various mass levels between 10−67 kilograms (kg) and 1052 kg. The least massive thing listed here is a graviton, and the most massive thing is the observable universe. Typically, an object having greater mass will also have greater weight (see mass versus weight), especially if the objects are subject to the same gravitational field strength.

Units of mass

[edit]
SI multiples of gram (g)
Submultiples Multiples
Value SI symbol Name Value SI symbol Name
10−1 g dg decigram 101 g dag decagram
10−2 g cg centigram 102 g hg hectogram
10−3 g mg milligram 103 g kg kilogram
10−6 g μg microgram (mcg) 106 g Mg megagram (tonne)
10−9 g ng nanogram 109 g Gg gigagram
10−12 g pg picogram 1012 g Tg teragram
10−15 g fg femtogram 1015 g Pg petagram
10−18 g ag attogram 1018 g Eg exagram
10−21 g zg zeptogram 1021 g Zg zettagram
10−24 g yg yoctogram 1024 g Yg yottagram
10−27 g rg rontogram 1027 g Rg ronnagram
10−30 g qg quectogram 1030 g Qg quettagram
Common prefixes are in bold face.[1]

The table above is based on the kilogram, the base unit of mass in the International System of Units (SI). The kilogram is the only standard unit to include an SI prefix (kilo-) as part of its name. The gram (10−3 kg) is an SI derived unit of mass. However, the names of all SI mass units are based on gram, rather than on kilogram; thus 103 kg is a megagram (106 g), not a *kilokilogram.

The tonne (t) is an SI-compatible unit of mass equal to a megagram (Mg), or 103 kg. The unit is in common use for masses above about 103 kg and is often used with SI prefixes. For example, a gigagram (Gg) or 109 g is 103 tonnes, commonly called a kilotonne.

Other units

[edit]

Other units of mass are also in use. Historical units include the stone, the pound, the carat, and the grain.

For subatomic particles, physicists use the mass-equivalent of an electronvolt (eV). At the atomic level, chemists use the mass of one-twelfth of a carbon-12 atom (the dalton). Astronomers use the mass of the sun (M☉).

The least massive things: below 10−24 kg

[edit]

Unlike other physical quantities, mass–energy does not have an a priori expected minimal quantity, or an observed basic quantum as in the case of electric charge. Planck's law allows for the existence of photons with arbitrarily low energies. Consequently, there can only ever be an experimental upper bound on the mass of a supposedly massless particle; in the case of the photon, this confirmed upper bound is of the order of 3×10−27 eV/c2 = 10−62 kg.

Factor (kg) Value Item
10−67 1.07×10−67 kg Graviton, upper bound (6×10−32 eV/c2)[2]
10−40 4.2×10−40 kg Mass equivalent of the energy of a photon at the peak of the spectrum of the cosmic microwave background radiation (0.235 meV/c2)[3]
10−36 1.8×10−36 kg 1 eV/c2, the mass equivalent of one electronvolt[4]
3.6×10−36 kg Electron neutrino, upper limit on mass (2 eV/c2)[5]
10−33
quectogram (qg)
10−31 9.11×10−31 kg Electron (511 keV/c2), the lightest elementary particle with a measured nonzero rest mass[6]
10−30
rontogram (rg) 		3.0–5.5×10−30 kg Up quark (as a current quark) (1.7–3.1 MeV/c2)[7]
10−28 1.9×10−28 kg Muon (106 MeV/c2)[8]
10−27
yoctogram (yg) 		1.661×10−27 kg Dalton (Da), a.k.a. unified atomic mass unit (u)
1.673×10−27 kg Proton (938.3 MeV/c2)[9][10]
1.674×10−27 kg Hydrogen atom, the lightest atom
1.675×10−27 kg Neutron (939.6 MeV/c2)[11][12]
10−26 1.2×10−26 kg Lithium atom (6.941 Da)
3.0×10−26 kg Water molecule (18.015 Da)
8.0×10−26 kg Titanium atom (47.867 Da)
10−25 1.1×10−25 kg Copper atom (63.546 Da)
1.6×10−25 kg Z boson (91.2 GeV/c2)[13]
2.2×10−25 kg Higgs boson (125 GeV/c2)
3.1×10−25 kg Top quark (173 GeV/c2),[14] the heaviest known elementary particle
3.2×10−25 kg Caffeine molecule (194 Da)
3.5×10−25 kg Lead-208 atom
4.9×10−25 kg Oganesson-294 atom, the heaviest known nuclide

10−24 to 10−18 kg

[edit]
Factor (kg) Value Item
10−24
zeptogram (zg) 		1.2×10−24 kg Buckyball molecule (720 Da)
10−23 1.4×10−23 kg Ubiquitin, a small ubiquitous protein (8.6 kDa)[15]
5.5×10−23 kg A typical protein (median size of roughly 300 amino acids ≈ 33 kDa)[16]
10−22 1.1×10−22 kg Haemoglobin A molecule in blood (64.5 kDa)[17]
10−21
attogram (ag) 		1.65×10−21 kg Double-stranded DNA molecule consisting of 1,578 base pairs (995 kDa)[18]
4.3×10−21 kg Prokaryotic ribosome (2.6 MDa)[19]
7.1×10−21 kg Eukaryotic ribosome (4.3 MDa)[19]
7.6×10−21 kg Brome mosaic virus, a small virus (4.6 MDa)[20]
10−20 3×10−20 kg Synaptic vesicle in rats (16.1 ± 3.8 MDa)[21]
6.8×10−20 kg Tobacco mosaic virus (41 MDa)[22]
10−19 1.1×10−19 kg Nuclear pore complex in yeast (66 MDa)[23]
2.5×10−19 kg Human adenovirus (150 MDa)[24]

10−18 to 10−12 kg

[edit]

Factor (kg) Value Item
10−18
femtogram (fg) 		1×10−18 kg HIV-1 virus[25][26]
4.7×10−18 kg DNA sequence of length 4.6 Mbp, the weight of the E. coli genome[27]
10−17 ~1×10−17 kg Vaccinia virus, a large virus[28]
1.1×10−17 kg Mass equivalent of 1 joule[29]
10−16 3×10−16 kg Prochlorococcus cyanobacteria, the smallest (and possibly most plentiful)[30] photosynthetic organism on Earth[31][32]
10−15
picogram (pg) 		1×10−15 kg E. coli bacterium (wet weight)[33]
6×10−15 kg DNA in a typical diploid human cell (approximate)
10−14 2.2×10−14 kg Human sperm cell[32][34]
6×10−14 kg Yeast cell (quite variable)[35][36]
10−13 1.5×10−13 kg Dunaliella salina, a green alga (dry weight)[37]

10−12 to 10−6 kg

[edit]
Scanning electron micrograph showing grains of sand

Factor (kg) Value Item
10−12
nanogram (ng) 		1×10−12 kg Average human cell (1 nanogram)[38]
2–3×10−12 kg HeLa human cell[39][40][41]
8×10−12 kg Grain of birch pollen[42]
10−11    
10−10 2.5×10−10 kg Grain of maize pollen[43]
3.5×10−10 kg Very fine grain of sand (0.063 mm diameter, 350 nanograms)
10−9
microgram (μg) 		3.6×10−9 kg Human ovum[32][44]
2.4×10−9 kg US RDA for vitamin B12 for adults[45]
10−8 10−8 kg Speculated approximate lower limit of the mass of a primordial black hole
1.5×10−8 kg US RDA for vitamin D for adults[46]
~2×10−8 kg Uncertainty in the mass of the International Prototype of the Kilogram (IPK) (±~20 μg)[47]
2.2×10−8 kg Planck mass,[48] can be expressed as the mass of a 2 Planck Length radius black hole
~7×10−8 kg One eyelash hair (approximate)[49]
10−7 1.5×10−7 kg US RDA for iodine for adults[50]
2–3×10−7 kg Fruit fly (dry weight)[51][52]

10−6 to 1 kg

[edit]
Factor (kg) Value Item
10−6
milligram (mg) 		2.5×10−6 kg Mosquitoes, common smaller species (about 2.5 milligrams),[53] grain of salt or sand,[54] medicines are typically expressed in milligrams[55]
10−5
centigram (cg) 		1.1×10−5 kg Small granule of quartz (2 mm diameter, 11 milligrams)[56]
2×10−5 kg Adult housefly (Musca domestica, 21.4 milligrams)[57]
10−4
decigram (dg) 		0.27–2.0×10−4 kg Range of amounts of caffeine in one cup of coffee (27–200 milligrams)[58]
1.5×10−4 kg A frame of 35mm motion picture film (157 milligrams)[59]
2×10−4 kg Metric carat (200 milligrams)[59]
10−3
gram (g) 		1×10−3 kg One cubic centimeter of water (1 gram)[60]
1×10−3 kg US dollar bill (1 gram)[61]
~1×10−3 kg Two raisins (approximately 1 gram)[62]
~8×10−3 kg Coins of one euro (7.5 grams),[63] one U.S. dollar (8.1 grams)[64] and one Canadian loonie (7 grams [pre-2012], 6.27 grams [2012-])[65]
10−2
decagram (dag) 		1.2×10−2 kg Mass of one mole (6.02214×1023 atoms) of carbon-12 (12 grams)
1.37×10−2 kg Amount of ethanol defined as one standard drink in the U.S. (13.7 grams)[66]
2–4×10−2 kg Adult mouse (Mus musculus, 20–40 grams)[67]
2.8×10−2 kg Ounce (avoirdupois) (28.3495 grams)[59]
4.7×10−2 kg Mass equivalent of the energy that is 1 megaton of TNT equivalent[59][68]
10−1
hectogram   (hg) 		0.1-0.2 kg An orange (100–200 grams)[69]
0.142-0.149 kg A baseball used in the major league.[70]
0.454 kg Pound (avoirdupois) (453.6 grams)[59]

1 kg to 105 kg

[edit]
Iron weights up to 50 kilograms depicted in Dictionnaire encyclopédique de l'épicerie et des industries annexes.
Factor (kg) Value Item
1 kg
kilogram (kg) 		1 kg One litre (0.001 m3) of water[71]
1–3 kg Smallest breed of dog (Chihuahua)[72]
1–3 kg Typical laptop computer, 2010[73]
1–3 kg Adult domestic tortoise
2.5–4 kg Newborn human baby[74]
4.0 kg Women's shot[75]
4–5 kg Housecat[76]
7.26 kg Men's shot[75]
101 9–27 kg Medium-sized dog[77]
10–30 kg A CRT computer monitor or television set[citation needed]
50 kg Large dog breed (Great Dane)
70 kg Adult human[78]
102 130–180 kg Mature lion, female (130 kg) and male (180 kg)[79]
200–250 kg Giant tortoise
240–450 kg Grand piano[80][81]
400–900 kg Dairy cow[82]
500–500,000 kg A teaspoon (5 ml) of white dwarf material (0.5–500 tonnes)[83][84]
635 kg Heaviest human in recorded history (Jon Brower Minnoch)
907.2 kg 1 short ton (2000 pounds - U.S.)[59]
103
megagram (Mg) 		1000 kg 1 tonne (U.S. spelling: metric ton)[59]
1000 kg 1 cubic metre of water[71]
1016.05 kg Ton (British) / 1 long ton (2240 pounds - U.S.)[59]
1300–1600 kg Typical passenger cars[85]
2700–6000 kg Adult elephant[86]
104 1.1×104 kg Hubble Space Telescope (11 tonnes)[87]
1.2×104 kg Largest elephant on record (12 tonnes)[88]
1.4×104 kg Big Ben (bell) (14 tonnes)[89]
2.7×104 kg ENIAC computer, 1946 (30 tonnes)[90]
4×104 kg Maximum gross mass (truck + load combined) of a semi-trailer truck in the EU (40–44 tonnes)[91]
5×104–6×104 kg Tank; Bulldozer (50–60 tonnes)
6.0×104 kg Largest single-piece meteorite, Hoba West Meteorite (60 tonnes)[92]
7.3×104 kg Largest dinosaur, Argentinosaurus (73 tonnes)[93]
105 1.74-1.83×105 kg Operational empty weight of a Boeing 747-300
1.8×105 kg Largest animal ever, a blue whale (180 tonnes)[94]
4.2×105 kg International Space Station (417 tonnes)[95]
6×105 kg World's heaviest aircraft: Antonov An-225 (maximum take-off mass: 600 tonnes, payload: 250 tonnes)[96]

106 to 1011 kg

[edit]

Factor (kg) Value Item
106
gigagram (Gg) 		1×106 kg Trunk of the giant sequoia tree named General Sherman, largest living tree by trunk volume (1121 tonnes)[97]
2.0×106 kg Launch mass of the Space Shuttle (2041 tonnes)[98]
6×106 kg Largest clonal colony, the quaking aspen named Pando (largest living organism) (6000 tonnes)[99]
7.8×106 kg Virginia-class nuclear submarine (submerged weight)[100]
107 1×107 kg Annual production of Darjeeling tea[101]
5.2×107 kg RMS Titanic when fully loaded (52,000 tonnes)[102]
9.97×107 kg Heaviest train ever: Australia's BHP Iron Ore, 2001 record (99,700 tonnes)[103]
108 6.6×108 kg Largest ship and largest mobile man-made object, Seawise Giant, when fully loaded (660,000 tonnes)[104]
7×108 kg Heaviest (non-pyramid) building, Palace of the Parliament in Bucharest, Romania[105]
109
teragram (Tg) 		4.3×109 kg Amount of matter converted into energy by the Sun each second[106]
6×109 kg Great Pyramid of Giza[107]
1010
 6×1010 kg Amount of concrete in the Three Gorges Dam, the world's largest concrete structure[108][109]
1011 ~1×1011 kg The mass of a primordial black hole with an evaporation time equal to the age of the universe[110]
2×1011 kg Amount of water stored in London storage reservoirs (0.2 km3)[111]
6×1011 kg Total mass of the world's human population[112]
5×1011 kg Total biomass of Antarctic krill, one of the most plentiful animal species on the planet in terms of biomass[113]

1012 to 1017 kg

[edit]
Factor (kg) Value Item
1012
petagram (Pg) 		0.8–2.1×1012 kg Global biomass of fish[114]
4×1012 kg Global annual human food production[115]
4×1012 kg World crude oil production in 2009 (3,843 Mt)[116]
5.5×1012 kg A teaspoon (5 ml) of neutron star material (5000 million tonnes)[117]
1013 1×1013 kg Mass of comet 67P/Churyumov–Gerasimenko[118]
4×1013 kg Global annual human carbon dioxide emission[119][120]
1014 1.05×1014 kg Global net primary production – the total mass of carbon fixed in organic compounds by photosynthesis each year on Earth[121]
7.2×1014 kg Total carbon stored in Earth's atmosphere[122]
1015
exagram (Eg) 		2.0×1015 kg Total carbon stored in the terrestrial biosphere[123]
3.5×1015 kg Total carbon stored in coal deposits worldwide[124]
1016 1×1016 kg 951 Gaspra, the first asteroid ever to be closely approached by a spacecraft (rough estimate)[125]
1×1016 kg Rough estimate of the total carbon content of all organisms on Earth.[126]
3×1016 kg Rough estimate of everything produced by the human species.[127]
3.8×1016 kg Total carbon stored in the oceans.[128]
1017 1.6×1017 kg Prometheus, a shepherd satellite for the inner edge of Saturn's F Ring[129]

1018 to 1023 kg

[edit]

Factor (kg) Value Item
1018
zettagram (Zg) 		5.1×1018 kg Earth's atmosphere[130]
5.6×1018 kg Hyperion, a moon of Saturn[129]
1019 3×1019 kg 3 Juno, one of the larger asteroids in the asteroid belt[131]
3×1019 kg The rings of Saturn[132]
1020 9.4×1020 kg Ceres, dwarf planet within the asteroid belt[133]
1021
yottagram (Yg) 		1.4×1021 kg Earth's oceans[134]
1.5×1021 kg Charon, the largest moon of Pluto[135]
2.9–3.7×1021 kg The asteroid belt[136]
4×1021 kg Haumea[137]
1022 1.3×1022 kg Pluto[135]
2.1×1022 kg Triton, largest moon of Neptune[138]
2.7×1022 kg Earth's crust[139]
7.3×1022 kg Earth's Moon[140]
1023 1.3×1023 kg Titan, largest moon of Saturn[141]
1.5×1023 kg Ganymede, largest moon of Jupiter[142]
3.3×1023 kg Mercury[143]
6.4×1023 kg Mars[144]

1024 to 1029 kg

[edit]
Jupiter is the most massive planet in the Solar System.
Factor (kg) Value Item
1024
ronnagram (Rg) 		4.9×1024 kg Venus[145]
6.0×1024 kg Earth[146]
1025 3×1025 kg Oort cloud[147]
8.7×1025 kg Uranus[148]
1026 1.0×1026 kg Neptune[149]
5.7×1026 kg Saturn[150]
1027
quettagram (Qg) 		1.9×1027 kg Jupiter[151]
1028 2–14×1028 kg Brown dwarfs (approximate)[152]
1029 3×1029 kg Barnard's Star, a nearby red dwarf[153]

1030 to 1035 kg

[edit]
Factor (kg) Value Item
1030 2×1030 kg The Sun[154] (one solar mass or M☉ = 1.989×1030 kg)
2.8×1030 kg Chandrasekhar limit (1.4 M☉)[155][156]
1031 4×1031 kg Betelgeuse, a red supergiant star (20 M☉)[157]
1032 4–7×1032 kg R136a1, the most massive of known stars (230 to 345 M☉)[158]
6–8×1032 kg Hyades star cluster (300 to 400 M☉)[159]
1033 1.6×1033 kg Pleiades star cluster (800 M☉)[160]
1034
1035 ~1035 kg Typical globular cluster in the Milky Way (overall range: 3×103 to 4×106 M☉)[161]
2×1035 kg Low end of mass range for giant molecular clouds (1×105 to 1×107 M☉)[162][163]
7.3×1035 kg Jeans mass of a giant molecular cloud at 100 K and density 30 atoms per cubic centimeter;[164]
possible example: Orion molecular cloud complex

1036 to 1041 kg

[edit]
Factor (kg) Value Item
1036 1.79×1036 kg The entire Carina complex.
2.4×1036 kg The Gould Belt of stars, including the Sun (1.2×106 M☉)[165]
7–8×1036 kg The supermassive black hole at the center of the Milky Way, associated with the radio source Sagittarius A* (3.7±0.2×106 M☉)[166]
8×1036 kg Omega centauri, the largest globular cluster in the Milky Way, containing approximately 10 million stars.
1037    
1038    
1039    
1040    
1041 1.98×1041 kg Phoenix A, the largest supermassive black hole, weighing 100 billion solar masses (1×1011 M☉)
4×1041 kg Visible mass of the Milky Way galaxy[167]

The most massive things: 1042 kg and greater

[edit]
Factor (kg) Value Item
1042 1.2×1042 kg Milky Way galaxy (5.8×1011 M☉)[168]
2–3×1042 kg Local Group of galaxies, including the Milky Way (1.29±0.14×1012 M☉)[168]
1043 5.37×1043 kg ESO 146-5, the heaviest known galaxy in the universe[169]
1044    
1045 1–2×1045 kg Local or Virgo Supercluster of galaxies, including the Local Group (1×1015 M☉)[170]
1046    
1047 2×1047 kg Laniakea Supercluster of galaxies, which encompasses the Virgo supercluster
1048 2×1048 kg Pisces–Cetus Supercluster Complex, a galaxy filament that includes the Laniakea Supercluster.
1049 4×1049 kg Hercules–Corona Borealis Great Wall, the largest structure in the known universe
1050    
1051    
1052 4.4506×1052 kg Mass of the observable universe as estimated by NASA
1.4×1053 kg Mass of the observable universe as estimated by the U.S. National Solar Observatory[171]

See also

[edit]

Notes

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Orders of magnitude (mass)

View on Grokipedia
from Grokipedia
Orders of magnitude (mass) refer to a that categorizes masses by their approximate power of ten in kilograms, facilitating comparisons across vastly disparate scales in physics and astronomy. This framework spans more than 80 orders of magnitude, from the tiniest known non-zero rest masses of neutrinos—estimated at less than 1 per squared, or roughly 10^{-36} kg—to the total ordinary matter in the , approximately 10^{53} kg. Key examples illustrate this breadth: subatomic particles like the at 10^{-31} kg, protons and neutrons at 10^{-27} kg, human-scale objects around 10^2 kg, at 10^{24} kg, the Sun at 10^{30} kg, and supermassive black holes exceeding 10^{40} kg. Such scaling underscores the hierarchical structure of matter in the , from quantum realms to cosmic aggregates, and is essential for order-of-magnitude estimations in scientific analysis where exact precision is secondary to grasping relative sizes.

Units of mass

SI units and prefixes

The (symbol: kg) is the base unit of mass in the (SI). Since the 2019 revision of the SI, the is defined by fixing the numerical value of the hh to exactly 6.62607015×10−346.62607015 \times 10^{-34} when expressed in the unit J⋅s, which is equal to kg⋅m²⋅s⁻¹, where the and the second are defined in terms of the cc and the hyperfine frequency ΔνCs\Delta \nu_{\text{Cs}}. This definition replaced the previous reliance on the international , a platinum-iridium artefact, ensuring the unit's stability and universality without reference to a physical object. To express orders of magnitude of mass in the SI system, decimal prefixes are affixed to the , denoting powers of ten as multiples or submultiples. These prefixes, standardized by the International Bureau of Weights and Measures (BIPM), facilitate the description of masses ranging from the subatomic to cosmic scales. The system includes 24 prefixes as of the 2022 update by the General Conference on Weights and Measures (CGPM), which added ronna and for multiples, and ronto and quecto for submultiples, extending the range beyond the previous yotta (10²⁴) and yocto (10⁻²⁴). The following table lists the SI prefixes relevant to mass, with their symbols, numerical factors, and corresponding powers of ten:
PrefixSymbolFactorPower of Ten
Q10³⁰10³⁰
ronnaR10²⁷10²⁷
yottaY10²⁴10²⁴
zettaZ10²¹10²¹
exaE10¹⁸10¹⁸
petaP10¹⁵10¹⁵
teraT10¹²10¹²
gigaG10⁹10⁹
megaM10⁶10⁶
kilok10³10³
hectoh10²10²
decada10¹10¹
(none)-10⁰10⁰
d10⁻¹10⁻¹
c10⁻²10⁻²
m10⁻³10⁻³
μ10⁻⁶10⁻⁶
n10⁻⁹10⁻⁹
picop10⁻¹²10⁻¹²
femtof10⁻¹⁵10⁻¹⁵
attoa10⁻¹⁸10⁻¹⁸
zeptoz10⁻²¹10⁻²¹
yoctoy10⁻²⁴10⁻²⁴
rontor10⁻²⁷10⁻²⁷
quectoq10⁻³⁰10⁻³⁰
For example, one microgram (μg) equals 10−610^{-6} kg, commonly used for small quantities like medications, while one yottagram (Yg) equals 102410^{24} kg, applicable to enormous masses such as planetary totals. These prefixes are not used with hecto-, deca-, deci-, or centi- in formal SI nomenclature for mass beyond specific contexts, as they are less common for orders of magnitude scaling. For bridging to non-SI systems, 1 kg is exactly equivalent to 2.2046226218487757 pounds (avoirdupois), as defined by the mutual conversion factor between the SI kilogram and the imperial pound.

Non-SI and specialized units

In addition to the (SI), various non-SI units of mass are employed in everyday, scientific, and specialized applications, often rooted in historical or field-specific conventions. These units facilitate measurements in contexts like , , and astronomy, where legacy systems or practical scales prevail. Conversions to SI kilograms (kg) are standardized for , though exact values depend on definitions established by international bodies. Imperial units, part of the avoirdupois system used primarily in the United States and historically in the United Kingdom, include the pound (lb), which is exactly 0.45359237 kg, equivalent to approximately 0.454 kg. The ounce (oz) is one-sixteenth of a pound, defined as exactly 28.349523125 grams (g), or about 28.35 g. The stone (st), common for body weight in some regions, equals 14 pounds, thus approximately 6.35 kg. In scientific fields such as chemistry and , the dalton (Da), also known as the unified atomic unit (u), serves as a standard for atomic and molecular masses; it is defined as 1/12 the of a free atom and equals 1.66053906892(52) × 10^{-27} kg. For approximate calculations, the of an atom or molecule in daltons corresponds closely to its atomic or molecular number, an value representing the sum of protons and neutrons. In , is often expressed via equivalents using Einstein's E = mc², where the (eV) unit of converts to as m = E / c²; for instance, 1 eV/c² ≈ 1.782662 × 10^{-36} kg, with the c exactly 299792458 m/s. This derivation yields the equivalent by dividing the in joules (1 eV = 1.60217662 × 10^{-19} J) by c². Astronomical measurements frequently use planetary and stellar masses for comparative scales. The (M☉) is approximately 1.989 × 10^{30} kg, serving as a reference for stellar objects. The (M⊕) is about 5.972 × 10^{24} kg, while the (M♃) is roughly 1.898 × 10^{27} kg, or 318 times Earth's mass. These values are derived from gravitational parameters and orbital dynamics observed by space agencies. Other specialized units include the carat (ct), standardized for gemstones at exactly 200 mg or 0.2 g, originating from the mass of seeds. The (gr), a historical unit from ancient and systems, equals approximately 64.8 mg and was used for small weights like bullets or medications. The (t), a metric unit though not an SI base, is defined as exactly 1000 kg and is widely used in industry for large-scale and .

Examples by order of magnitude

Below 10^{-24} kg

Masses below 10−2410^{-24} kg pertain to the scales of fundamental particles in and , where the describes known elementary constituents, while hypothetical entities like gravitons probe regimes. These masses are typically expressed in units (eV/c2c^2) due to relativistic conventions, with conversions to kilograms revealing their minuscule scale relative to everyday matter. Experimental determinations rely on high-precision accelerators like the LHC and spectrometers like , with no new elementary particles discovered as of LHC Run 3 data through 2025, upholding predictions. Hypothetical particles occupy the lowest mass ranges here. The , a proposed massless mediator of gravity in theories, has stringent upper limits from astrophysical and cosmological observations; a recent analysis of the dipole convergence yields mg<5×10−32m_g < 5 \times 10^{-32} eV/c2c^2 (equivalent to <8.9×10−68< 8.9 \times 10^{-68} kg), tightening constraints by a factor of 2.5×1082.5 \times 10^8 over bounds. , fundamental fermions with tiny masses confirmed by oscillation experiments, have effective mass scales informed by both oscillations and direct measurements. Oscillation data from global fits indicate mass-squared differences Δm212≈7.41×10−5\Delta m_{21}^2 \approx 7.41 \times 10^{-5} eV2^2 (solar) and Δm322≈2.44×10−3\Delta m_{32}^2 \approx 2.44 \times 10^{-3} eV2^2 (atmospheric), implying at least one neutrino mass above ≈0.05\approx 0.05 eV/c2c^2 (≈8.9×10−38\approx 8.9 \times 10^{-38} kg) in the normal hierarchy; the experiment's 2025 direct kinematic bound sets an upper limit of mνe<0.45m_{\nu_e} < 0.45 eV/c2c^2 (<8.0×10−37< 8.0 \times 10^{-37} kg) at 90% confidence from 259 days of tritium data. These bounds, updated from 2020s experiments like NOν\nuA and T2K, highlight neutrinos' role in beyond-Standard-Model physics, such as the mass hierarchy and . Among confirmed elementary particles, leptons and quarks exemplify this range. The electron, the lightest charged lepton, has mass me=0.51099895000(15)m_e = 0.51099895000(15) MeV/c2c^2 (9.1093837015×10−319.1093837015 \times 10^{-31} kg), determined from precision and QED tests. Light quarks, up and down, constitute protons and neutrons; in the MS‾\overline{\rm MS} scheme at 2 GeV, mu=2.20±0.07m_u = 2.20 \pm 0.07 MeV/c2c^2 (≈3.92×10−30\approx 3.92 \times 10^{-30} kg) and md=4.69±0.05m_d = 4.69 \pm 0.05 MeV/c2c^2 (≈8.36×10−30\approx 8.36 \times 10^{-30} kg), extracted from simulations of hadron masses and decays. Heavier quarks like the top, the most massive , weigh mt=172.69±0.30m_t = 172.69 \pm 0.30 GeV/c2c^2 (3.078×10−253.078 \times 10^{-25} kg), measured via LHC reconstructions of top-pair production and decays, with the 2024 PDG average reflecting Run 2 and early Run 3 data. Subatomic composites approach the upper end of this range while emphasizing bare particle focus. The hydrogen-1 ion (protium nucleus, essentially a bare proton) has mass mp=1.67262192369(51)×10−27m_p = 1.67262192369(51) \times 10^{-27} kg, derived from and CODATA adjustments. Theoretical scales provide context: the Planck mass mP=ℏc/G=2.176434×10−8m_P = \sqrt{\hbar c / G} = 2.176434 \times 10^{-8}
Add your contribution
Related Hubs
User Avatar
No comments yet.