Why is lb the symbol for pound?
By Anne Marie Helmenstine Ph.D. ThoughtCo
Have you ever wondered why we use the symbol “lb” for the “pounds” unit? The word “pound” is short for “pound weight,” which was libra pondo in Latin. The librapart of the phrase meant both weight or balance scales. The Latin usage was shortened to libra, which naturally was abbreviated “lb”. We adopted the pound part from pondo, yet kept the abbreviation for libra.
There are different definitions for the mass of a pound, depending on the country. In the United States, the modern pound unit is defined to be 2.20462234 pounds per metric kilogram. There are 16 ounces in 1 pound. However, in Roman times, the libra(pound) was about 0.3289 kilograms and was divided into 12 uncia or ounces.
- Fletcher, Leroy S.; Shoup, Terry E. (1978). Introduction to Engineering. Prentice-Hall. ISBN 978-0135018583.
- United States National Bureau of Standards (1959-06-25). “Notices “Refinement of values for the yard and the pound“.
- Zupko, Ronald Edward (1985). Dictionary of Weights and Measures for the British Isles: The Middle Ages to the 20th Century. DIANE Publishing. ISBN 0-87169-168-X.