Convert Ounces to Grams
Convert ounces (oz) to grams (g) instantly, with the exact formula, worked examples, and the ounce-vs-troy-ounce gotchas.
- Milligram (mg)28,349.52
- Gram (g)28.34952
- Kilogram (kg)0.02835
- Tonne (t)0.000028
- Ounce (oz)1
- Pound (lb)0.0625
- Don (돈)7.559873
- Geun (근, 600g)0.047249
- Nyang (냥)0.755987
- Gwan (관)0.00756
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The oz-to-gram formula
Converting ounces to grams is a simple multiplication: 1 oz = 28.35 g, so multiply the number of ounces by 28.35. For example, 4 oz = 4 × 28.35 = 113.4 g, 8 oz = 226.8 g, and 16 oz (one pound) = 453.6 g. To go the other way, divide grams by 28.35 — so 100 g works out to about 3.53 oz. The ounce here is the avoirdupois (weight) ounce; its exact value is 28.3495 g, but rounding to 28.35 introduces almost no error for everyday use.
Where you'll actually use it
US recipes are the classic case. A stick of butter is 4 oz (113.4 g) and a bag of chocolate chips is usually 12 oz (340.2 g), so weighing them in grams is far more accurate than measuring by volume in cups. Buying coffee? A 12 oz bag is 340 g, and the roughly 0.5 oz of beans per cup is about 14 g. The conversion also helps with shipping weights on imported parcels, boxing gloves (e.g. 10 oz = 283.5 g), and fabric weights quoted in ounces per square yard.
Easy mistakes to avoid
First, precious metals like gold and silver use the troy ounce, not the avoirdupois one. A troy ounce is 31.1035 g — noticeably heavier than 28.35 g — so never price bullion with 28.35. Second, a fluid ounce (fl oz) measures volume, not weight: 1 fl oz is about 29.57 mL, an entirely different quantity. It roughly matches for water by coincidence, but not for oil or honey. Third, rounding 28.3495 down to 28.35 lets tiny errors accumulate on large weights, so keep the decimals when you need precision.
Frequently asked questions
How many grams is exactly 1 ounce?
For the avoirdupois (weight) ounce, 1 oz = 28.3495 g, usually rounded to 28.35 g. Multiply ounces by 28.35 to get grams — for example, 3 oz = 85.05 g.
How many grams is 4 oz of butter in a recipe?
4 × 28.35 = 113.4 g. In US recipes, one stick of butter is commonly listed as 4 oz (about 113 g). 8 oz is 226.8 g, and a full pound (16 oz) is 453.6 g.
Can I use 28.35 g for one ounce of gold?
No. Gold, silver, and other precious metals are measured in troy ounces, where 1 troy oz = 31.1035 g. Using 28.35 g would undercount by about 2.75 g per ounce, so use the troy ounce for bullion pricing.