Illustration of 16 ounces making 1 pound and 14 pounds making 1 stone

Calculators & everyday math

Ounces, Pounds, and Stone Explained

Ounces, pounds, and stone belong to one family of units, but they are divided unevenly — 16 ounces to a pound and 14 pounds to a stone. This guide shows how they fit together, how body weight in stone converts to kilograms, and two units that are easy to confuse with them.

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How they fit together

How they fit together comparison
UnitEqualsIn grams
1 ounce1/16 pound28.349523125
1 pound16 ounces453.59237
1 stone14 pounds6,350.29318

Body weight in stone

In the UK and Ireland, body weight is often given in stone and pounds. Convert the stone to pounds first, add the extra pounds, then convert: 11 st 7 lb is 11 × 14 + 7 = 161 lb, which is 73.02837157 kg.

Troy ounces are heavier

Gold, silver, and other precious metals are weighed in troy ounces of 31.1034768 grams — about 10% more than the everyday avoirdupois ounce of 28.349523125 grams. The Weight Converter uses the everyday ounce.

Fluid ounces measure volume

A fluid ounce is a unit of volume, not weight. A US fluid ounce of water weighs about 1.04 ounces, but a fluid ounce of oil or flour weighs a different amount, so the two can’t be swapped without knowing the density.

Ounces, Pounds, and Stone FAQ

How many ounces are in a pound?
16.
How many pounds are in a stone?
14.
What is 10 stone in kilograms?
10 stone is 140 pounds, which is 63.5029318 kg.
Is a fluid ounce the same as an ounce?
No. A fluid ounce measures volume and an ounce measures weight.
Why is stone still used?
It is a traditional unit that remains common for body weight in the UK and Ireland, even though most other measurements there are metric.

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