Molar mass of carbon-12 = 12.000 000 0126 × 10−3 kg·mol⁻¹

Value
12.000 000 0126 × 10−3
Unit
kg·mol⁻¹
Uncertainty
0.000 000 0037 × 10⁻³
Copy-ready
12.0000000126e-3

The molar mass of carbon-12.

Exactly 12 g/mol before 2019; now a measured value, just as close to it.

NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.

Electrical, thermal and X-ray constants

Angstrom starConductance quantumCopper x unitElectron charge to mass quotientFermi coupling constantFirst radiation constantHartree energyJosephson constantLattice parameter of siliconLattice spacing of ideal Si (220)Loschmidt constant (273.15 K, 101.325 kPa)Magnetic flux quantumMolar mass constantMolar mass of carbon-12Molar Planck constantMolar volume of siliconMolybdenum x unitNeutron-proton mass differenceProton charge to mass quotientQuantum of circulationSackur-Tetrode constant (1 K, 101.325 kPa)Second radiation constantVon Klitzing constantWeak mixing angleWien frequency displacement law constantW to Z mass ratio

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All physical constants

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