How to use this ounce converter
Enter the number of ounces and select the destination unit; grams are selected initially. You can reverse the menus for grams-to-ounces calculations. Before entering a value, verify that the source says oz as mass rather than fl oz for volume or troy oz for precious metals.
How the calculation works
One avoirdupois ounce is exactly one-sixteenth of the international pound. Since the pound equals exactly 0.45359237 kilogram, one ounce equals exactly 0.028349523125 kilogram or 28.349523125 grams.
The same word ounce appears in several measurement systems. A US fluid ounce and an imperial fluid ounce measure volume, not mass. A troy ounce is approximately 31.1034768 grams and is used in precious-metal contexts. This calculator deliberately uses only the ordinary avoirdupois mass ounce.
Ingredient mass cannot be inferred from fluid volume without density, and labeled package quantities can have legal tolerances. The converter translates the number entered; it does not determine product density, net contents, or measurement uncertainty.
Formulas
Ounces to grams
Ounces to pounds
Ounces to kilograms
Worked examples
Convert 8 ounces to grams
8 × 28.349523125 = exactly 226.796185 grams before rounding.
Convert 24 ounces to pounds
24 ÷ 16 = exactly 1.5 pounds.
Convert 4 ounces to kilograms
4 × 0.028349523125 = exactly 0.1133980925 kilogram.
Common uses
Packaged goods and postal estimates
Convert small labeled masses from ounces to grams or pounds while checking the package uses ordinary avoirdupois ounces.
Cooking by mass
Translate mass-based recipe quantities when a scale uses grams and the recipe specifies ounces. Do not use the same factor for fluid ounces.
Small objects and materials
Compare jewelry, components, samples, or household objects only after confirming that the source does not use troy ounces or another specialized system.
Accuracy and limitations
This converter uses the avoirdupois ounce of exactly 28.349523125 grams. Fluid ounces and troy ounces are deliberately excluded.
Package tolerances, scale resolution, moisture, and material variation can matter more than the final displayed digits. Round according to the measurement purpose.
Frequently asked questions
How many grams are in an ounce?
One avoirdupois ounce equals exactly 28.349523125 grams.
Is an ounce the same as a fluid ounce?
No. This ounce measures mass; a fluid ounce measures volume.
Is a troy ounce included?
No. A troy ounce is a different unit used mainly for precious metals and is not available in this converter.
How many ounces are in a pound?
One international avoirdupois pound contains exactly 16 ounces.
Can I convert a recipe's cups to ounces?
Only if you know whether ounces means mass or volume and, for a mass conversion from volume, the ingredient's density.
How should I round the answer?
Match the precision of the source measurement or the rule governing the application; extra displayed digits are not extra measured accuracy.