Convert Ounces to Grams

About converting Ounces to Grams

Ounces (oz) and Grams (g) are both units of weight & mass, so converting between them is a single multiplication: multiply your Ounces figure by 28.3495. Ten Ounces comes to 283.4952 Grams, and a hundred works out at 2,834.95 Grams.

Rule of thumb: going from Ounces to Grams multiplies, so the figure always grows — one Ounce is already 28.3495 Grams. If your answer came out smaller, you have the conversion the wrong way round.

What is an Ounce?

The ounce here is the avoirdupois ounce, one sixteenth of a pound, and the qualifier matters. The troy ounce used to price gold and silver is noticeably heavier, so a "one ounce" gold coin is not an ounce of anything else — a confusion that has cost people real money. Muddier still is the fluid ounce, which measures volume rather than mass and differs between the US and the UK. The name comes from the Latin uncia, a twelfth part: it was a twelfth of the Roman libra, and the move to sixteen ounces to the pound came later.

What is a Gram?

The gram sits oddly in SI: the kilogram, not the gram, is the official base unit of mass, which makes mass the only quantity whose base unit carries a prefix built into its name. The gram was defined in 1795 as the mass of a cubic centimetre of water at the melting point of ice — a definition that tied mass neatly to length and made the young metric system self-consistent. It survives as the working unit of nutrition labels, recipes, postage and laboratory work: anything small enough that kilograms would force you into decimals.

To put both in perspective: a slice of sandwich bread weighs about an ounce, while a paperclip weighs about a gram.

The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Grams to Ounces converter, or browse all Weight & Mass converters.