oz to Grams: Conversion Chart for Cooking and Post

"Ounce" refers to three different units, and mixing them up is the single most common conversion mistake in cooking.

Weight (avoirdupois) ounce 1 oz = 28.3495 g. This is the one on food packaging and postal scales. grams = ounces × 28.3495 ounces = grams ÷ 28.3495

Fluid ounce A measure of volume, not weight. 1 US fl oz = 29.5735 ml; 1 UK fl oz = 28.4131 ml. It only equals 28.35 g by coincidence, and only for water.

Troy ounce Used for precious metals: 1 troy oz = 31.1035 g. Gold priced "per ounce" always means troy, which is why a gold ounce is about 10% heavier than a kitchen ounce.

Chart 1 oz = 28 g. 2 oz = 57 g. 4 oz = 113 g. 8 oz = 227 g. 12 oz = 340 g. 16 oz (1 lb) = 454 g.

Cooking note A US recipe calling for "8 oz of flour" means weight — 227 g — while "8 oz of milk" almost always means fluid ounces, or 237 ml. When in doubt, liquids are fluid, solids are weight.