Ounce (oz)

The avoirdupois ounce (oz) is 1/16 of a pound, exactly 28.349523125 g. It is not the same as the troy ounce used for gold or the fluid ounce used for volume.

Symbol: oz

Quantity: mass (commonly called weight)

SI relation: 1 oz = 0.028349523125 kg (exact)

Derivation: 1 oz = 1/16 lb = 28.349523125 g (exact)

Exact: yes, by definition

Reference conditions. Avoirdupois system: 1 lb = 16 oz = 7000 grains = 0.45359237 kg exactly (1959 agreement).

Typical uses

Food and parcel weights in the US
Recipes and portion sizes
Postage

Convert ounces to other units

1 oz in other weight and mass units
Conversion	1 oz equals	Reverse
ounce to kilogram	0.02834952313 kg	kilogram to ounce
ounce to gram	28.34952313 g	gram to ounce
ounce to milligram	28349.52313 mg	milligram to ounce
ounce to pound	0.0625 lb	pound to ounce
ounce to microgram	28349523.13 µg	microgram to ounce
ounce to metric ton	0.00002834952313 t	metric ton to ounce
ounce to stone	0.004464285714 st	stone to ounce
ounce to short ton	0.00003125 ton (US)	short ton to ounce
ounce to troy ounce	0.9114583333 oz t	troy ounce to ounce
ounce to long ton	0.00002790178571 ton (UK)	long ton to ounce
ounce to grain	437.5 gr	grain to ounce
ounce to carat	141.7476156 ct	carat to ounce

Open the Weight and Mass Converter to convert any value between all units.

Sources

Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "ounce (avoirdupois) (oz)".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.

Cite this page

APA

Scientific Converters. (2026, October 15). Ounce (oz). Retrieved October 17, 2026, from https://scientificconverters.com/units/ounce/

IEEE

Scientific Converters, "Ounce (oz)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/ounce/