Ounce conversions

Convert ounces to

ounce (Imp. & US customary unit of mass), pl. ounces, abbr. oz

The ounce conversion selector on this page selects the mass/weight measurement unit to convert to starting from ounces (oz). To make a conversion starting from a unit of mass other than ounce, simply click on the "Reset" button.

About ounce

The international avoirdupois ounce (or simply "ounce") is a unit of mass in the Imperial and US customary systems of units equal to 0.028349523125 kilograms (1 oz = 0.028349523125 kg), the base unit of mass in the International System of Units (SI).

One ounce (oz) is also equal to 28.349523125 grams (g), or 28,349.523125 milligrams (mg) or 28.349523125 × 106 micrograms (μg) (SI units of mass), or 0.0625 pounds (lb), or 0.9114583 troy ounces (oz t) or 437.5 grains (gr), which are US customary / Imperial units of mass.

The ounce definition varies depending on the system of units used, as follows:

  • The avoirdupois ounce (or simply "ounce"), equal to 0.0625 pounds
  • The troy ounce, equal to 0.0685714286 pounds
  • The Apothecaries' ounce, equal to 0.0685714286 pounds
  • The Dutch metric ounce, equal to 0.220462262 pounds
  • The Spanish ounce, equal to 0.0633829004 pounds
  • The Chinese metric ounce, equal to 0.110231131 pounds
  • The Maria Theresa ounce, equal to 0.0618767022 pounds

The ounce is commonly used as a unit of mass / weight in the United States and the United Kingdom.

Note:
The abbreviation "oz" for ounce comes from the old Italian word "onza".

Symbol: oz

Plural: ounces

Also called: ounce (plural: ounces, symbol: oz)

Back to ounce (oz)

DefinitionSelectorTop