kilogram
kgmass · International · Modern
SI base unit of mass. The Planck constant is fixed exactly at 6.62607015×10^-34 J·s, which defines the kilogram through the metre and second.
Converter
mass · International · Modern
gram
gexact
- Record
- M008
- Definition quality
- Standardized
- Conversion mode
- multiplicative
- Calculator
- Fully calculable
Definition
1 g = 0.001 kg.
Reference value
One gram is equal to 0.001 kilograms.
History & use
The gram is the SI-prefixed submultiple used routinely for smaller masses.
Modern use
Current-use record in the project inventory; exact scope should follow the definition and regional/system context shown here.
Did you know?
The kilogram is the only SI base-unit name that already contains an SI prefix.
Sources & evidence
Related measurements
mass · International · Modern
1 tonne = 1000 kg.
mass · UK / US · Modern / historical
1 avoirdupois ounce = exactly 1/16 international pound = 0.028349523125 kg.
mass · UK / US · Modern / historical
1 international avoirdupois pound = exactly 0.45359237 kg.
stone
stmass · UK / US · Modern / historical
1 stone = 14 lb = exactly 6.35029318 kg using the international pound.
mass · International · Modern
Dalton/u is 1/12 of the mass of a free carbon-12 atom in its ground state. CODATA 2022: 1.66053906892(52)×10^-27 kg.
approx.mass · Ancient Greece / Rome · Antiquity
Greek talent was not one universal standard.
variantmass · Ancient Greece / Rome · Antiquity
Modern scholarship cautions that proposed SI values span roughly 322.56–330 g.
approx.