Convert stones to pounds

The stone and the pound are two imperial units of mass held together by a fixed ratio: one stone equals fourteen pounds.[1]

The pound carries the hard definition. It weighs exactly 0.45359237 kilograms, and the same figure applies in the United Kingdom and in the United States.[2] The stone takes its value from there: fourteen of those pounds come to 6.35029318 kilograms.

In Britain and Ireland the two units describe one thing together: body weight. A British speaker gives it as whole stones plus the remaining pounds, an American gives the same weight in pounds alone. Converting stones to pounds is therefore a move from the British notation to the American one.

One stone is 14 pounds. The formula has a single step: pounds = stones × 14.

The multiplier is a whole number, so whole stones give a result with no decimal part. Twelve stone comes to 168 pounds. Twenty stone comes to 280 pounds. Seven stone is exactly 98 pounds.

The same sum works in your head in two steps. Multiply the stones by ten, then add four times the same figure. Thirteen stone gives 130 plus 52, which is 182 pounds.

The same rule covers the values in between. Half a stone is 7 pounds, because half of fourteen falls on a whole number. A quarter stone comes to 3.5 pounds.

The opposite direction is handled by the pounds to stones converter, and the move into metric by the stone to kilograms converter.

English keeps two pounds in circulation. The converter works with the avoirdupois pound of 453.59237 grams, the one behind every weight on this page.[2] The field label says so directly: it reads “Pounds (lb)”.

The other one is the troy pound of 373.24172 grams, which holds twelve troy ounces. The ounce inside it is the unit gold, silver and platinum are priced in.[3] Body weight and stones stay entirely on the avoirdupois side.

The gap shows up quickly on real numbers. Twelve stone is 168 avoirdupois pounds, which comes to 76.2 kilograms. The same count in troy pounds would come to 62.7 kilograms, some thirteen and a half kilograms lower. The pound table below sets the values side by side.

Beyond body weight the stone stays in use across British and Irish sport: professional boxing, wrestling and horse racing.[1]

In the Grand National, the best known British steeplechase, the top weight a horse carries is 11 st 12 lb.[4] In pounds alone that is 166. Eleven stone accounts for 154 pounds, and the remainder adds another twelve.

Boxing sets its division limits in pounds, and British commentary reads them back in stones. Several of them land on a round figure there. The flyweight limit stops at 112 pounds, exactly eight stone. The featherweight limit stops at 126 pounds, exactly nine.[5]

Two more divisions land on half stones. The welterweight limit is 147 pounds, ten and a half stone. The light heavyweight limit is 175 pounds, twelve and a half. Read in stones, the whole set falls on whole and half values.