gram
gmass · International · Modern
1 g = 0.001 kg.
Converter
mass · troy weight · Current specialist + historical
troy ounce
exact
- Record
- M078
- Definition quality
- Exact by definition
- Conversion mode
- multiplicative
- Calculator
- Fully calculable
Definition
1 troy oz = 480 grains = 31.1034768 g exactly
Reference value
One troy ounce is exactly 0.0311034768 kilograms.
History & use
Troy weight survives as a specialist mass system for precious metals; its ounce contains 480 grains.
Modern use
Modern use is context-dependent and varies by region or measurement system.
Sources & evidence
Source tier — · confidence high
- Office of Weights and Measures, National Institute of Standards and Technology — https://nvlpubs.nist.gov/nistpubs/hb/2026/NIST.HB.44-2026.pdf
- Office of Weights and Measures, National Institute of Standards and Technology — https://www.nist.gov/pml/owm/nist-handbook-133-current-edition
- National Bureau of Standards / Commonwealth national standards laboratories — https://www.nist.gov/pml/us-surveyfoot
- National Institute of Standards and Technology — https://www.nist.gov/pml/special-publication-811
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variant