【How-to】How many pounds in a stone

The stone (st) is a unit of measure equal to 14 pounds (lb) avoirdupois, or 6.3503 kilograms (kg). … In the U.K. people may be said to weigh, e.g., “11 stone 4” (11 stones and 4 pounds), rather than “72 kilograms”, or “158 pounds” as in the U.S.