Ounces to Grams
Convert ounces to grams in your browser, with a warning about fluid ounces, which measure something else entirely.
g = oz × 28.349523125
NIST SP 811 (2008), Appendix B.8 — ounce (avoirdupois) (oz) to kilogram (kg) = 2.834 952 E−02
Recipes are where this one lives. American baking is written in ounces and cups, European baking in grams, and the difference matters more in baking than almost anywhere else, because flour and sugar ratios do not forgive being eyeballed. An ounce is 28.349523125 grams exactly.
How it is calculated
g = oz × 28.349523125
The factor is exact because the pound is defined as exactly 0.45359237 kilograms and an ounce is a sixteenth of a pound. Rounding to 28 is out by more than 1 %, which on a kilogram of flour is a missing tablespoon.
Source: NIST SP 811 (2008), Appendix B.8 — ounce (avoirdupois) (oz) to kilogram (kg) = 2.834 952 E−02
Common values
| ounces | grams |
|---|---|
| 1 | 28.349523 |
| 2 | 56.699046 |
| 4 | 113.39809 |
| 6 | 170.09714 |
| 8 | 226.79619 |
| 12 | 340.19428 |
| 16 | 453.59237 |
| 20 | 566.99046 |
| 24 | 680.38856 |
| 32 | 907.18474 |
| 35.274 | 1,000.0011 |
Questions people ask
- Is a fluid ounce the same thing?
- No, and mixing them up ruins recipes. A fluid ounce measures volume, an ounce measures mass. They happen to be close for water, which is exactly why the mistake survives — for flour, honey or butter they are nowhere near each other.
- What is a troy ounce?
- A different unit, used for precious metals: 31.1034768 grams, about 10 % heavier than the ordinary ounce. Gold prices are quoted per troy ounce, so converting one with the other factor gets the value wrong.
- How many ounces in a pound?
- Sixteen, which is 453.59237 grams. Recipes calling for a pound of something are asking for roughly 454 grams — the half-kilo often substituted is about 10 % more.
Found a problem, or want more?
A number that disagrees with its source is a defect, not a rounding preference.
What did you enter, what did the tool show, and what did you expect instead? If you have a source that disagrees with ours, a link to it is the most useful thing you can send.
Opens your mail app with the page and tool already filled in.
Related tools
Grams to Ounces
Convert grams to ounces for recipes and postage. One avoirdupois ounce is a sixteenth of a pound, which works out at 28.349523125 grams exactly.
Pounds to Kilograms
Convert pounds to kilograms in your browser. A pound is exactly 0.45359237 kilograms, fixed by agreement in 1959.
Cups to Milliliters
Convert US cups to milliliters in your browser, and find out why a cup of flour is not a reliable measurement.