To convert pounds (lbs) to stones (st), divide the number of pounds by 14. For example, 150 pounds divided by 14 equals approximately 10.71 stones. In everyday UK usage, this is usually expressed as 10 stone and 10 pounds (since 0.71 × 14 = 10).

A stone is a unit of mass in the Imperial system, primarily used in the United Kingdom and Ireland for measuring body weight. One stone is equal to exactly 14 pounds (lbs) or approximately 6.35 kilograms. The plural form is typically ‘stone’ (e.g., ’11 stone’) rather than ‘stones’ when used with a number.

There are exactly 14 pounds in one stone. This conversion factor is fixed in the Imperial system of weights. To convert any weight from stones to pounds, simply multiply the number of stones by 14.

To express a total weight in pounds as stones and pounds, divide the total pounds by 14. The whole number result is the stones, and the remainder is the pounds. For example, 180 lbs ÷ 14 = 12 with a remainder of 12. So, 180 lbs is 12 stone 12 lbs.

The use of stones for body weight is a historical tradition in the UK. Before the metric system, the stone was a common unit for weighing agricultural goods and people. It provides a convenient middle ground between pounds (which result in large numbers like 150 or 200) and kilograms, making it easier to talk about and track body weight changes in everyday conversation.

First, convert the stones and pounds into total pounds by multiplying the stones by 14 and adding the remaining pounds. Then, multiply the total pounds by 0.453592 to get kilograms. For example, 10 stone 5 lbs is 145 lbs total. 145 × 0.453592 = 65.77 kg.

The stone is almost exclusively used in the United Kingdom and Ireland for body weight. It is not used in the United States (which uses pounds) or in countries that have fully adopted the metric system (which use kilograms). Some Commonwealth countries historically used it, but it has largely fallen out of official use elsewhere.

Technically, stones and pounds are units of mass, while weight is the force of gravity on that mass. However, in everyday, non-scientific contexts—like measuring body weight or groceries—people use ‘weight’ and ‘mass’ interchangeably. A weighing scale actually measures the force of gravity but is calibrated to display mass in stones, pounds, or kilograms under standard Earth gravity.