About the Ounces to Grams
This ounces to grams converter turns a weight in ounces (oz) into grams (g), and also shows kilograms and pounds. It uses the standard avoirdupois ounce — the one on food packaging, kitchen scales and postal rates — and offers the troy ounce as an option for gold, silver and other precious metals.
It is ideal for following an American or British recipe on a metric scale, checking a parcel weight, converting a nutrition serving size, or working out how many grams are in a coin or bar priced per troy ounce. A reference table lists the conversions cooks and bakers look up most.
The factor is exact: one avoirdupois ounce is 28.349523125 g (1/16 of a pound of 453.59237 g), and one troy ounce is 31.1034768 g. Note this tool is for weight; for liquids measured in fluid ounces use the oz to ml converter instead.
With the default inputs, the grams is 226.796 g. Change any value above to recalculate instantly.
How to use the ounces to grams
- 1Enter the weight in ounces (decimals such as 3.5 are fine).
- 2Leave the standard ounce selected, or pick troy for gold and silver.
- 3Read the result in grams, with kilograms and pounds below.
- 4Use the chart and table for quick kitchen conversions.
Formula and method
The international avoirdupois pound is defined as exactly 453.59237 grams and has 16 ounces, so one ounce is 453.59237 ÷ 16 = 28.349523125 g. Multiply ounces by that factor to get grams, and divide grams by 1,000 for kilograms.
The troy ounce, used only for precious metals, is defined as exactly 31.1034768 g, about 9.7% heavier. Fluid ounces measure volume, not weight, so they need a different conversion.
- oz
- Avoirdupois ounce = 28.349523125 g
- oz t
- Troy ounce = 31.1034768 g
- g
- Grams
Worked examples
Half a pound: 8 oz of butter
8 × 28.3495 = 226.8 g, exactly half a pound. Many recipes round this to 225 g.
3.5 oz serving
3.5 × 28.3495 = 99.2 g — very close to 100 g, which is why 100 g packs are often labelled 3.5 oz.
4 troy ounces of silver
4 × 31.1034768 = 124.41 g. The same weight is about 4.39 standard ounces.
Frequently asked questions
How many grams are in an ounce?+
One standard (avoirdupois) ounce is exactly 28.349523125 grams, usually rounded to 28.35 g. For quick kitchen maths many people use 28 or 30 g.
How many grams in a troy ounce?+
A troy ounce, used for gold, silver and platinum, is 31.1034768 grams — about 2.75 g more than a standard ounce.
How many ounces is 100 grams?+
100 g ÷ 28.3495 = 3.527 ounces. A common rounding on packaging is 3.5 oz.
Are ounces and fluid ounces the same?+
No. Ounces measure weight and fluid ounces measure volume. One US fluid ounce of water weighs about 29.6 g, which is close to but not the same as 28.35 g.
How many ounces are in a pound?+
There are 16 ounces in a pound, so 1 lb = 16 × 28.3495 = 453.59 g.