Convert Ounce to Gram

To convert ounces to grams, multiply by 28.3495231 — the exact factor follows from the 1959 international definition of the pound (453.59237 g) and the 16-ounce pound. One ounce is therefore 453.59237 ÷ 16 = 28.3495231 g, with no approximation. A 6 oz chicken breast is 170.1 g; a 16 oz steak is exactly 453.59 g — essentially a metric pound.

Food packaging in the United States typically lists weight in both ounces and grams on the nutrition label, making this conversion familiar even if not consciously calculated. A 12 oz can of soda holds 340.2 g of liquid; a 1.5 oz (42.5 g) serving of cheese is a common nutritional portion size in American diet-tracking apps.

The avoirdupois-versus-troy distinction matters here too. When a jeweller quotes a ring setting at '5 oz,' they almost certainly mean troy ounces — 5 × 31.1035 = 155.5 g. A kitchen scale reading of 5 oz would give only 141.75 g. If you are buying or selling metal by weight, confirm which ounce the seller is using before multiplying. In non-precious-metal contexts — food, pharmaceuticals, parcels — avoirdupois is always assumed.