# Definition:Avoirdupois/Pound

## Definition

The pound is an avoirdupois unit of mass.

It is defined as being exactly $453 \cdotp 59237$ grams.

### Conversion Factors

 $\ds$  $\ds 1$ pound avoirdupois $\ds$ $=$ $\ds 16$ ounces avoirdupois $\ds$ $=$ $\ds 7 \, 000$ grains $\ds$ $=$ $\ds 453 \cdotp 59237$ grams $\quad$ (exact) $\ds$ $=$ $\ds 0 \cdotp 45359237$ kilograms $\quad$ (exact)

### Symbol

$\mathrm {lb}$

The symbol for the pound is $\mathrm {lb}$.

Its $\LaTeX$ code is \mathrm {lb} .

This derives from the libra (Roman pound) from which the pound evolved.

It always needs to be distinguished from the pound sterling, whose symbol is $\pounds$.

## Linguistic Note on Avoirdupois

The word avoirdupois derives from the Norman French word whose literal translation is goods (that is property, or things owned) of weight.

The avoir part also means to have in modern French, and derives from the Latin habere.

It is pronounced something like av-wah-doo-pwah, although Francophones will be aware that there are further subtleties to this.