The factor
g = oz × 28.349523125. An ounce is a sixteenth of a pound, and the pound is exactly 453.59237 g, so the factor is exact. Recipes often round it to 28 or 30 g; 30 is 6% high, which matters more in baking than in cooking.
Worked examples
Rounded to two decimal places:
| Ounces | Grams |
|---|---|
| 0.5 oz | 14.17 g |
| 1 oz | 28.35 g |
| 2 oz | 56.7 g |
| 4 oz | 113.4 g |
| 8 oz | 226.8 g |
| 12 oz | 340.19 g |
| 16 oz | 453.59 g |
16 oz is a pound, 453.59 g, and a steak sold as 8 oz is 226.8 g.
Questions
Is a fluid ounce the same as an ounce?
No. An ounce is a weight and a fluid ounce a volume. A US fluid ounce of water weighs about 1.04 oz. For liquids, use ml to oz.
What about troy ounces?
Gold and silver are weighed in troy ounces of 31.1034768 g, about 10% heavier. This page uses the ordinary ounce only.