Home › Cooking Converters › Ounces to Grams Converter
Convert avoirdupois ounces to grams or grams to ounces for ingredient weighing, packaged food quantities and recipe scaling. This converter handles mass, not fluid ounces. Choose the direction carefully because fluid ounces measure volume and require a density to convert into grams.
Ounces to grams converter
Results are estimates based on the values you enter. Nothing you type is sent to or stored on our servers.
Mass conversion formula
One international avoirdupois ounce is 28.349523125 grams. The forward conversion is grams = ounces × 28.3495. The reverse conversion is ounces = grams ÷ 28.3495. The calculator uses the rounded factor 28.3495, which is adequate for everyday cooking and food portions.
Sixteen avoirdupois ounces make one avoirdupois pound, so one pound is 453.59237 grams. This relationship is useful for checking a result when converting a package weight or a larger ingredient quantity.
Worked examples
Four ounces convert to about 113.4 g, close to the mass of a US butter stick. Eight ounces convert to about 226.8 g. Sixteen ounces convert to about 453.6 g, or one pound.
In the reverse direction, 100 g is about 3.53 oz and 500 g is about 17.64 oz. The result may display a few decimal places, but a kitchen scale and the precision of the original package measurement determine the practical accuracy.
How to use the converter
- Enter a non-negative quantity in the amount field.
- Select ounces to grams or grams to ounces.
- Calculate and read the converted mass. Use the reverse direction when adapting a metric recipe to an imperial kitchen scale.
Ounces are not fluid ounces
An ounce (oz) is a unit of mass. A US fluid ounce (fl oz) is a unit of volume. They are not interchangeable. For water, one US fluid ounce has a mass close to one ounce because water density is near 1 g/mL, but oil, honey, flour and other ingredients have different densities. Never convert fluid ounces to grams without identifying the ingredient and its density.
Precision and rounding
The conversion factor is fixed, but the input may not be exact. A package label may round to the nearest ounce, and a household scale may display whole grams. For a home recipe, rounding to the nearest gram or tenth of an ounce is generally more meaningful than reporting many decimal places.
For commercial weighing, laboratory work or regulated labeling, use a calibrated instrument and the precision required by the applicable standard. This page is a kitchen conversion aid, not a legal-for-trade weighing instrument.
Frequently asked questions
How many grams are in one ounce?
One avoirdupois ounce is exactly 28.349523125 g. The converter uses 28.3495 g per ounce.
Is 8 oz equal to 8 fluid ounces?
No. Eight ounces is a mass; eight fluid ounces is a volume. Their gram weights depend on the liquid or ingredient.
How many ounces are in 100 grams?
100 g is approximately 3.53 avoirdupois ounces.
Related tools and reference
For larger quantities, use the Pounds to Kilograms Converter. For liquid volume, use the US Fluid Ounces to mL Calculator. Reference factors: NIST approximate US customary-to-metric conversions.