Convert Ounces to Stones

About converting Ounces to Stones

Ounces (oz) and Stones (st) are both units of weight & mass, so converting between them is a single multiplication: multiply your Ounces figure by 0.004464. Ten Ounces comes to 0.04464 Stones, and a hundred works out at 0.4464 Stones.

Rule of thumb: going from Ounces to Stones divides, so the figure always shrinks — it takes about 224 Ounces to make a single Stone. If your answer came out bigger, 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 Stone?

The stone is fourteen pounds and, outside Britain and Ireland, essentially extinct. There it is still how people state body weight: a Briton says "eleven stone four", meaning eleven stone plus four pounds, and the plural stays stone in that construction — never "eleven stones". Americans give the identical weight as a single number in pounds, which is why British figures baffle them. The unit predates standardisation and was once a moving target, with a stone of wool, cheese or glass all weighing different amounts, and it is no longer permitted for trade in the UK at all.

To put both in perspective: a slice of sandwich bread weighs about an ounce, while most adults weigh somewhere between 9 and 14 stone.

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