Definition:FPS/Pound

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Definition

The pound is the FPS unit of measurement of mass, which has a number of different standards.

The most common standard is for it to be defined in kilograms to be exactly $0.453 \, 592 \, 37 \ \mathrm{kg}$.


Pound Avoirdupois

The pound is an avoirdupois unit of mass.

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

\(\ds \) \(\) \(\ds 1\) 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)


Apothecaries' Pound

The apothecaries' pound is an apothecaries' unit of mass.

\(\ds \) \(\) \(\ds 1\) apothecaries' pound
\(\ds \) \(=\) \(\ds 12\) apothecaries' ounces
\(\ds \) \(=\) \(\ds 5 \, 760\) grains
\(\ds \) \(=\) \(\ds 373 \cdotp 24\) grams
\(\ds \) \(=\) \(\ds 1\) troy pound


Troy Pound

\(\ds \) \(\) \(\ds 1\) troy pound
\(\ds \) \(=\) \(\ds 12\) troy ounces
\(\ds \) \(=\) \(\ds 5 \, 760\) grains
\(\ds \) \(=\) \(\ds 1\) apothecaries' pound
\(\ds \) \(\approx\) \(\ds 373 \cdotp 24\) grams


Libra (Roman Pound)

$1$ libra $= 12$ unciae.

Its value in modern units is estimated to be approximately $5 \, 076$ grains or $329$ grams.


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 $\pounds$.


Sources