A stone (st) is a unit of weight equal to 14 pounds (lb) avoirdupois, or 6.3503 kilograms (kg) ). The stone measurement is mostly used in the United Kingdom, Australia, and Ireland for measuring human body weight. To convert a weight in stones to pounds, you can multiply the weight in stones by 14, since 1 stone is equal to 14 pounds. For example, 5 stones is equal to 70 pounds (5 x 14) .