1 ounce is 28.3 grams. The number below is worked from the US measure, and the chart covers the amounts either side of it so you can read off whatever your recipe actually calls for.
Ounces to grams chart
| Ounces | Grams |
|---|---|
| 1/4 oz | 7.09 g |
| 1/2 oz | 14.2 g |
| 1 oz | 28.3 g |
| 2 oz | 56.7 g |
| 3 oz | 85 g |
| 4 oz | 113 g |
| 6 oz | 170 g |
| 8 oz | 227 g |
| 12 oz | 340 g |
| 16 oz | 454 g |
How this conversion is defined
This one is fixed. The pound is defined as exactly 453.59237 grams, and the ounce as one sixteenth of that, so 1 ounce comes to 28.3 grams with no rounding built in and no dependence on what is being weighed.
The troy ounce is a different unit
Gold and silver are weighed in troy ounces, at 31.10 g each, against 28.35 g for the ounce used for food. A troy ounce is about ten per cent heavier, so quoting a metal price against the wrong ounce misstates it by roughly a tenth.
Nothing in a kitchen uses the troy ounce. It is worth knowing about only so that a figure found online can be read against the right unit.
Going the other way: grams to ounces
The same relationship read backwards. This is the chart you want when the recipe gives grams and your measuring kit is marked in ounces.
| Grams | Ounces |
|---|---|
| 2 1/2 g | 0.088 oz |
| 5 g | 0.176 oz |
| 10 g | 0.353 oz |
| 20 g | 0.705 oz |
| 28.3 g | 1 oz |
| 30 g | 1.06 oz |
| 40 g | 1.41 oz |
| 60 g | 2.12 oz |
| 80 g | 2.82 oz |
| 120 g | 4.23 oz |
| 160 g | 5.64 oz |
Measuring it without getting it wrong
A kitchen scale settles this outright. Put the empty container on, press tare so it reads zero, then add until you reach the figure. Anything measured by weight comes out the same every time, regardless of how it was packed.
Check that the scale is switched to the unit you actually want. Most read grams and ounces both ways, and a number read against the wrong unit is the commonest reason a doubled recipe fails.
When rounding is safe and when it is not
The exact figure is 28.3 grams. Rounding it to a convenient number costs you very little on a single quantity and adds up quickly once a recipe is doubled or tripled.
A useful rule: round freely for anything savoury that you can taste and adjust, and keep the decimal for baking, brining and anything involving yeast. Those are the cases where the ratio, not the amount, is doing the work.
Where this comes up
Most recipes are written for one system and cooked in another. American recipes measure by cup, European ones by gram, and anything from a bakery measures by weight because that is what the result depends on.
Knowing that 1 ounce is 28.3 grams is what lets you cook from any of them.
Related conversions
For every kitchen figure in one place, see the full conversion chart.
