Ounces to Grams
Ounces to Grams — convert oz to g instantly. Also shows kilograms, milligrams, and pounds. Accurate to 6 decimals. Free, no signup.
About Ounces to Grams
Ounces to Grams is a simple, accurate weight converter. Type any value in ounces and the result appears instantly — in grams, kilograms, milligrams, and pounds. Useful when a recipe lists ingredients by ounce but your scale only measures grams, when a postage form needs metric weight, or when you’re cross-referencing nutrition labels that use different units.
The exact conversion factor is 1 ounce = 28.349523125 grams. This is the international avoirdupois ounce — the standard for cooking, postage, and general weight in the US, UK, Canada, and most English-speaking countries. Many recipes and packaging round this to 28 g, but for baking or anything where precision matters, the full-precision value matters too.
When precision matters
For everyday cooking, rounding 1 oz to 28 g is fine. For baking and pastry, it isn’t. A loaf of bread that calls for 16 oz of flour needs 453.6 g exactly — and most home bakers who switch to gram measurements notice their results becoming more consistent. The same applies to portioning protein for fitness goals, weighing supplements, or calibrating any small-scale workflow. Use the rounded value when it doesn’t matter, the exact value when it does.
Avoirdupois vs troy ounce
The ounce on this calculator is the avoirdupois ounce — the everyday weight. There’s another ounce called the troy ounce, used almost exclusively for precious metals. A troy ounce is about 10% heavier (31.1035 g vs 28.3495 g). If you’re weighing gold, silver, platinum, or palladium, use a troy ounce calculator. For everything else, this is the right one.
Why grams beat ounces for accuracy
The metric system was designed for precision and clean math. A gram is one thousandth of a kilogram, exactly. An ounce is 1/16th of a pound, which is 1/2240th of an imperial ton — a confusing chain of fractions. Most kitchen scales now read in both units, and switching to grams reduces rounding errors when scaling recipes up or down.
Free, no signup, accurate to six decimal places.
Frequently asked questions
Exactly 28.349523125 grams. This is the international avoirdupois ounce — the standard used in the US, UK, Canada, and most English-speaking countries. The calculator uses the full-precision value, so 1 oz returns 28.3495 g, not the rounded 28 g you'll see in recipe books.
Avoirdupois — the everyday ounce used in cooking, postage, and general weight. If you're converting precious metals (gold, silver, platinum), use a troy ounce calculator instead: 1 troy oz = 31.1034768 g, which is about 10% heavier than an avoirdupois ounce.
Rounding for convenience. Recipe books and food packaging round 1 oz to 28 g (or sometimes 30 g) because most home kitchens don't have scales accurate to a tenth of a gram. For everyday cooking the rounded value is fine. For baking, supplements, or anything where precision matters, use the exact conversion this tool provides.
Divide grams by 28.349523125. Example: 100 g ÷ 28.349523125 = 3.5274 oz. Or use our [Grams to Ounces](/calculator/grams-to-ounces) calculator (coming soon).