Pounds (lb)

What is a pound?

The pound is the unit of mass used for body weight, food and goods in the United States, and alongside the kilogram in the United Kingdom and Canada. It is exactly 0.45359237 kilograms, and it is divided into 16 ounces.

The abbreviation "lb" comes from the Roman libra, a unit of about 327 grams. The pound on this page is the avoirdupois pound; the troy pound used for precious metals is lighter, at 12 troy ounces.

What pounds are used for

• Body weight in the US (and with stones in the UK)
• Meat, produce and deli food in US grocery stores
• Luggage limits (50 lb for most US checked bags)
• Shipping weights and vehicle payloads

Pounds in real life

• A pound of butter is four sticks
• A standard bowling ball is up to 16 lb
• A gallon of water weighs about 8.34 lb
• The average newborn weighs about 7.5 lb

One pound is about as heavy as 9.1 large eggs, or about as heavy as 9.9 golf balls, or about as heavy as 2.5 apples, or about as heavy as 2.4 smartphones.

History of the pound

Many pounds were used in medieval England, including the tower pound and the merchants' pound. The avoirdupois pound of 7,000 grains became standard for most goods in the 14th century. In 1959 the United States and the Commonwealth defined it as exactly 0.45359237 kg.