Why this conversion is exact (unlike cups)
Ounces and grams are both units of mass/weight, so converting between them is pure arithmetic — 1 oz = 28.3495g, always, no matter whether you're weighing flour, butter, or lead. This is fundamentally different from a cups-to-grams conversion, where cups measure volume and the gram weight depends entirely on the ingredient's density. If a recipe calls for "8 oz of butter," that's always 226.8g regardless of context — but "1 cup of butter" and "1 cup of flour" weigh very different amounts in grams, because they're different ingredients occupying the same volume.
A common source of confusion: fluid ounces
There's a second kind of "ounce" — the fluid ounce (fl oz), a unit of volume used for liquids, which is completely different from the weight ounce this calculator converts. A fluid ounce of water happens to weigh almost exactly 1 oz by weight (since water's density is close to 1g/mL), which is where a lot of the confusion comes from — but a fluid ounce of honey or oil weighs a different amount by weight, since they're denser or lighter than water. If your recipe says "8 fl oz of milk," that's a volume measurement (equivalent to 1 cup), not a weight one — use the milliliters-to-cups converter for that instead of this page.
Quick reference chart
| Ounces | Grams |
|---|---|
| 1 oz | 28.3g |
| 2 oz | 56.7g |
| 4 oz | 113.4g |
| 8 oz | 226.8g |
| 16 oz (1 lb) | 453.6g |
FAQ
Is this the same as fluid ounces? No — this converts weight ounces (oz) to grams. Fluid ounces measure volume; see our milliliters-to-cups converter for that.
Why do US recipes use ounces and UK/most other recipes use grams? It's a legacy of the US retaining imperial units for everyday cooking while most of the world moved to metric. Neither is more "accurate" — they're just different unit systems for the same underlying weight.