Convert Kilograms to Ounces

About converting Kilograms to Ounces

Kilograms (kg) and Ounces (oz) are both units of weight & mass, so converting between them is a single multiplication: multiply your Kilograms figure by 35.274. Ten Kilograms comes to 352.7396 Ounces, and a hundred works out at 3,527.4 Ounces.

Rule of thumb: going from Kilograms to Ounces multiplies, so the figure always grows — one Kilogram is already 35.274 Ounces. If your answer came out smaller, you have the conversion the wrong way round.

What is a Kilogram?

The kilogram was the last SI unit still defined by a physical object — the International Prototype Kilogram, a platinum-iridium cylinder kept in a vault near Paris since 1889. The problem was that it drifted. Careful comparisons against its official copies showed the masses diverging by tens of micrograms, and because the prototype simply was the kilogram by definition, there was no way to say which side had changed. In 2019 it was redefined in terms of the Planck constant, so any properly equipped lab can now realise a kilogram from physics rather than from an artefact.

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.

To put both in perspective: a liter of water weighs about a kilogram, while a slice of sandwich bread weighs about an ounce.

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