Pounds to stone:
divide by 14

How many stone is a pound?

One pound is 0.07142857143 stone, because a stone is exactly 14 pounds. In practice you divide the pounds by 14, which gives a decimal stone figure and, once you split off the remainder, the familiar 'stone and pounds' form.

This page covers the pounds-to-stone direction, which is what you do when a US-style scale or an online form gives pounds and you want the UK way of saying it. The factor is exact, so the only rounding is in how many decimals you keep.

The pounds to stone formula

1. 1Divide the pounds by 14 and keep the whole number: this is the stone.
2. 2Multiply the stone by 14 and subtract from the original pounds: this is the remainder.
3. 3Write the answer as stone and pounds, or keep the decimal if a form needs one number.

Chart: pounds to stone

Values are rounded to four decimals. The decimal part is a fraction of 14, not of 10, so 7.1429 stone is 7 stone and 2 pounds, not 7 stone 14 pounds.

The decimal trap: 10.7 stone is not 10 stone 7

The most common error is reading a decimal as pounds. Take 150 lb: 150 ÷ 14 = 10.714 stone. That is 10 stone and 0.714 × 14 = 10 pounds, so 10 st 10 lb. Someone who reads 10.7 as 'ten stone seven' is off by three pounds.

Another check: 200 lb ÷ 14 = 14.2857, so 14 stone with a remainder of 200 − 196 = 4 pounds, or 14 st 4 lb. A weight of 182 lb is exactly 13 stone because 13 × 14 = 182. These conversions only restate the figure; treat any weight goal as a question for a health professional.

More examples: round and awkward weights

Weights that are multiples of 14 pounds convert to a whole number of stone. 133 lb is 9.5 stone, which is 9 st 7 lb. 168 lb is exactly 12 stone and 224 lb is exactly 16 stone. A weight of 100 lb is 7.1429 stone, or 7 st 2 lb.

When you convert for a form, check which format it asks for. Some want a single decimal such as 12.5, others want two boxes for stone and pounds. For 175 lb the answers are 12.5 and 12 st 7 lb, and both describe the same weight.

Common mistakes when converting lbs to stone

• Dividing by 10 or 16 instead of 14.
• Reading the decimal as the pounds, so 10.7 st becomes '10 st 7 lb'.
• Dropping the remainder and rounding 10.7 stone to 11 stone in a record that needs pounds.
• Multiplying instead of dividing. Stone is the larger unit, so the stone number must be smaller.