Definition:Imperial
Definition
The imperial system is a system of measurement based on traditional established folk measures.
Its base units can be understood as being the FPS Base Units
Imperial / FPS Base Units
| Name | Unit symbol | Dimension | Symbol |
|---|---|---|---|
| foot | $\mathrm {ft}$ | Length | $l$ |
| pound | $\mathrm {lb}$ | Mass | $m$ |
| second | $\mathrm s$ | Time | $t$ |
Foot
The foot is the FPS base unit and an imperial unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | foot | |||||||||||
| \(\ds \) | \(=\) | \(\ds 12\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 3\) | yard | |||||||||||
| \(\ds \) | \(=\) | \(\ds 30 \cdotp 48\) | centimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 3048\) | metres | \(\quad\) (exact) |
Pound
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 $0.453 \, 592 \, 37 \ \mathrm{kg}$.
Second
The second is the SI base unit of time, and also therefore of the MKS system.
It is also the base unit of time for the FPS and CGS systems.
The second is defined as:
- the duration of $9 \ 192 \ 631 \ 770$ periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium $133$ atom at rest at $0 \ \mathrm K$.
Imperial Length Measure
The imperial units of length are as follows:
Microinch
The microinch is an imperial unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | microinch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 10^{-3}\) | mil | |||||||||||
| \(\ds \) | \(=\) | \(\ds 10^{-6}\) | inch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 0254\) | micrometre | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 54 \times 10^{-5}\) | millimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 54 \times 10^{-8}\) | metres | \(\quad\) (exact) |
Mil
The mil is an imperial unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | mil | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {1000}\) | inch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1000\) | microinches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 25 \cdotp 4\) | micrometres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 0254\) | millimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 54 \times 10^{-5}\) | metres | \(\quad\) (exact) |
Inch
The inch is an imperial and FPS unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | inch | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {12}\) | foot | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 54\) | centimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 0254\) | metres | \(\quad\) (exact) |
Link
| \(\ds \) | \(\) | \(\ds 1\) | link | |||||||||||
| \(\ds \) | \(=\) | \(\ds 7 \cdotp 92\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {100}\) | chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 201 \cdotp 168\) | millimetres |
Foot
The foot is the FPS base unit and an imperial unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | foot | |||||||||||
| \(\ds \) | \(=\) | \(\ds 12\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 3\) | yard | |||||||||||
| \(\ds \) | \(=\) | \(\ds 30 \cdotp 48\) | centimetres | \(\quad\) (exact) | ||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 3048\) | metres | \(\quad\) (exact) |
Yard
| \(\ds \) | \(\) | \(\ds 1\) | yard | |||||||||||
| \(\ds \) | \(=\) | \(\ds 3\) | feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 36\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 91 \cdotp 44\) | centimetres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 9144\) | metres |
Rod, Pole or Perch
| \(\ds \) | \(\) | \(\ds 1\) | rod, pole or perch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5 \tfrac 1 2\) | yards | |||||||||||
| \(\ds \) | \(=\) | \(\ds 16 \tfrac 1 2\) | feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 198\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 502 \cdotp 92\) | centimetres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5 \cdotp 0292\) | metres |
Chain
| \(\ds \) | \(\) | \(\ds 1\) | chain | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | rods, poles or perches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 22\) | yards | |||||||||||
| \(\ds \) | \(=\) | \(\ds 66\) | feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 792\) | inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 100\) | links | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20 \cdotp 1168\) | metres |
Furlong
| \(\ds \) | \(\) | \(\ds 1\) | furlong | |||||||||||
| \(\ds \) | \(=\) | \(\ds 10\) | chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 40\) | rods, poles or perches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 220\) | yards | |||||||||||
| \(\ds \) | \(=\) | \(\ds 660\) | feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 201 \cdotp 168\) | metres |
International Mile
The (international) mile is an imperial unit of length.
| \(\ds \) | \(\) | \(\ds 1\) | (international) mile | |||||||||||
| \(\ds \) | \(=\) | \(\ds 8\) | furlongs | |||||||||||
| \(\ds \) | \(=\) | \(\ds 80\) | chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 320\) | rods, poles or perches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1760\) | yards | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5280\) | feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1609 \cdotp 344\) | metres | \(\quad\) (exact) |
League
| \(\ds \) | \(\) | \(\ds 1\) | league | |||||||||||
| \(\ds \) | \(\) | \(\ds 3\) | (international) miles | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5280\) | yards | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 2\) | leuca | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 3000\) | paces | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4828 \cdotp 032\) | metres (exactly) |
Imperial Area Measure
The imperial units of area are based on a system of units in which each unit is the square of a corresponding imperial length unit.
The imperial units of area are as follows:
Square Inch
One square inch is equal to a square of side $1$ inch in length.
| \(\ds \) | \(\) | \(\ds 1\) | square inch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 6 \cdotp 4516\) | \(\ds = 2 \cdotp 54^2\) | square centimetres |
The definition is exact.
Square Foot
One square foot is equal to a square of side $1$ foot in length.
| \(\ds \) | \(\) | \(\ds 1\) | square foot | |||||||||||
| \(\ds \) | \(=\) | \(\ds 144\) | \(\ds = 12^2\) | square inches |
Square Yard
One square yard is equal to a square of side $1$ yard in length.
| \(\ds \) | \(\) | \(\ds 1\) | square yard | |||||||||||
| \(\ds \) | \(=\) | \(\ds 9\) | \(\ds = 3^2\) | square feet | ||||||||||
| \(\ds \) | \(=\) | \(\ds 1296\) | \(\ds = 36^2\) | square inches |
Square Rod, Pole or Perch
One square rod, pole or perch is equal to a square of side $1$ rod, pole or perch in length.
| \(\ds \) | \(\) | \(\ds 1\) | square rod, pole or perch | |||||||||||
| \(\ds \) | \(=\) | \(\ds 30 \tfrac 1 4\) | \(\ds = \paren {5 \tfrac 1 2}^2\) | square yards | ||||||||||
| \(\ds \) | \(=\) | \(\ds 272 \tfrac 1 4\) | \(\ds = \paren {16 \tfrac 1 2}^2\) | square feet |
Square Chain
One square chain is equal to a square of side $1$ chain in length.
| \(\ds \) | \(\) | \(\ds 1\) | square chain | |||||||||||
| \(\ds \) | \(=\) | \(\ds 16\) | \(\ds = 4^2\) | square rods, poles or perches | ||||||||||
| \(\ds \) | \(=\) | \(\ds 484\) | \(\ds = 22^2\) | square yards |
Rood
One rood is equal to an oblong measuring $1$ chain by $2 \frac 1 2$ chains.
| \(\ds \) | \(\) | \(\ds 1\) | rood | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \tfrac 1 2\) | square chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 40\) | \(\ds = 4 \times 10\) | square rods, poles or perches | ||||||||||
| \(\ds \) | \(=\) | \(\ds 1210\) | \(\ds = 22 \times 55\) | square yards | ||||||||||
| \(\ds \) | \(=\) | \(\ds 10 \, 890\) | \(\ds = 66 \times 165\) | square feet |
Acre
One acre is equal to an oblong measuring $1$ chain by $1$ furlong.
That is, measuring $4$ rods, poles or perches by $10$ chains.
| \(\ds \) | \(\) | \(\ds 1\) | acre | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | roods | |||||||||||
| \(\ds \) | \(=\) | \(\ds 10\) | square chains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 160\) | \(\ds = 4 \times 40\) | square rods, poles or perches | ||||||||||
| \(\ds \) | \(=\) | \(\ds 4840\) | \(\ds = 22 \times 220\) | square yards | ||||||||||
| \(\ds \) | \(\approx\) | \(\ds 0 \cdotp 4\) | hectares |
Square Mile
One square mile is equal to a square whose side measures $1$ mile.
| \(\ds \) | \(\) | \(\ds 1\) | square mile | |||||||||||
| \(\ds \) | \(=\) | \(\ds 640\) | \(\ds = 8 \times 80\) | acres |
Imperial Volume Measure
The imperial units of volume are based on a binary system, in which each unit is a factor of $2$ larger than the next smaller unit.
Fluid Ounce
The fluid ounce is an imperial unit of volume.
It is also part of the apothecaries' system of volume.
| \(\ds \) | \(\) | \(\ds 1\) | fluid ounce | |||||||||||
| \(\ds \) | \(=\) | \(\ds 8\) | fluid drachms | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {20}\) | (imperial) pint | |||||||||||
| \(\ds \) | \(=\) | \(\ds 28 \cdotp 41306 \, 25\) | millilitres |
Gill
| \(\ds \) | \(\) | \(\ds 1\) | gill | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5\) | fluid ounces | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 14206 \, 53125\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 142 \cdotp 06531 \, 25\) | millilitres |
Chopin
| \(\ds \) | \(\) | \(\ds 1\) | chopin | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | gills | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 28413 \, 0625\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 284 \cdotp 13062 \, 5\) | millilitres |
Pint
The pint is an imperial unit of volume.
It is also part of the apothecaries' system of volume.
| \(\ds \) | \(\) | \(\ds 1\) | pint (imperial) | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20\) | fluid ounces | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | chopins | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 5682 \, 6125\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 568 \cdotp 26125\) | millilitres |
Quart
| \(\ds \) | \(\) | \(\ds 1\) | quart (imperial) | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | pints (imperial) | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1 \cdotp 13652 25\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1 \, 136 \cdotp 5225\) | millilitres |
Pottle
| \(\ds \) | \(\) | \(\ds 1\) | pottle | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | quarts | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \cdotp 273045\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2 \, 273 \cdotp 045\) | millilitres |
Gallon
The (imperial) gallon is an imperial unit of volume.
It is defined as the volume of $10$ pounds of water under a specific set of conditions.
| \(\ds \) | \(\) | \(\ds 1\) | imperial gallon | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | pottles | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | quarts | |||||||||||
| \(\ds \) | \(=\) | \(\ds 277 \cdotp 4198\) | cubic inches | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 1605\) | cubic feet | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4 \, 546 \cdotp 09\) | millilitres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4 \cdotp 54609\) | litres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4 \cdotp 54609 \times 10^{-3}\) | cubic metres |
Peck
| \(\ds \) | \(\) | \(\ds 1\) | peck | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | (imperial) gallons | |||||||||||
| \(\ds \) | \(=\) | \(\ds 9 \cdotp 09218\) | litres |
Demi-Bushel
| \(\ds \) | \(\) | \(\ds 1\) | demi-bushel | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | pecks | |||||||||||
| \(\ds \) | \(=\) | \(\ds 18 \cdotp 18436\) | litres |
Bushel
| \(\ds \) | \(\) | \(\ds 1\) | bushel | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | demi-bushels | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 03636 \, 872\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 36 \cdotp 36872\) | litres |
Kilderkin
| \(\ds \) | \(\) | \(\ds 1\) | kilderkin | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | bushels | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 07273 \, 744\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 72 \cdotp 73744\) | litres |
Barrel
| \(\ds \) | \(\) | \(\ds 1\) | barrel | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | kilderkins | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 14547 \, 488\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 145 \cdotp 47488\) | litres |
Hogshead
| \(\ds \) | \(\) | \(\ds 1\) | hogshead | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | barrels | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 29094 \, 976\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 290 \cdotp 94976\) | litres |
Pipe
| \(\ds \) | \(\) | \(\ds 1\) | pipe | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | hogsheads | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 58189 \, 952\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 581 \cdotp 89952\) | litres |
Tun
| \(\ds \) | \(\) | \(\ds 1\) | tun | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | pipes | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1 \cdotp 16379 \, 904\) | cubic metres | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1 \, 163 \cdotp 79904\) | litres |
Imperial Mass Measure
There are three imperial systems of measurement of mass:
Grain
The grain is the imperial unit of mass which is used as the basis of all three of the imperial weight systems.
| \(\ds \) | \(\) | \(\ds 1\) | grain | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {437 \cdot 5}\) | ounce avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 64 \cdotp 8\) | milligrams |
Avoirdupois
Dram
The dram is an avoirdupois unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | dram | |||||||||||
| \(\ds \) | \(=\) | \(\ds 27 \cdotp 34375\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds \dfrac 1 {16}\) | ounce avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 1 \cdotp 77\) | grams |
Ounce
| \(\ds \) | \(\) | \(\ds 1\) | ounce avoirdupois | |||||||||||
| \(\ds \) | \(=\) | \(\ds 16\) | drams | |||||||||||
| \(\ds \) | \(=\) | \(\ds 437 \cdotp 5\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 28 \cdotp 34952 \, 3125\) | grams | |||||||||||
| \(\ds \) | \(=\) | \(\ds 0 \cdotp 02834 \, 95231 \, 25\) | kilograms |
The gram / kilogram equivalent is defined to be exact.
Pound
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) |
Stone
| \(\ds \) | \(\) | \(\ds 1\) | stone | |||||||||||
| \(\ds \) | \(=\) | \(\ds 14\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(=\) | \(\ds 224\) | ounces avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 6 \, 350 \cdotp 29318\) | grams |
The gram equivalent is exact.
Quarter
| \(\ds \) | \(\) | \(\ds 1\) | quarter | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2\) | stone | |||||||||||
| \(\ds \) | \(=\) | \(\ds 28\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 12 \cdotp 7\) | kilograms |
Hundredweight
The hundredweight is an avoirdupois unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | hundredweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | quarters | |||||||||||
| \(\ds \) | \(=\) | \(\ds 8\) | stone | |||||||||||
| \(\ds \) | \(=\) | \(\ds 112\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 50 \cdotp 8\) | kilograms |
Ton
The ton is an avoirdupois unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | ton | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20\) | hundredweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 80\) | quarters | |||||||||||
| \(\ds \) | \(=\) | \(\ds 160\) | stone | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2240\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 1016\) | kilograms | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 1 \cdotp 016\) | tonnes |
Avoirdupois: Short Variants
Short Hundredweight
The short hundredweight is an avoirdupois unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | short hundredweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 100\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 45 \cdotp 359\) | kilograms |
Quarter
| \(\ds \) | \(\) | \(\ds 1\) | quarter | |||||||||||
| \(\ds \) | \(=\) | \(\ds 5\) | short hundredweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 500\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 181 \cdotp 44\) | kilograms |
Short Ton
| \(\ds \) | \(\) | \(\ds 1\) | short ton | |||||||||||
| \(\ds \) | \(=\) | \(\ds 4\) | quarters | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20\) | short hundredweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 2000\) | pounds avoirdupois | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 907 \cdot 2\) | kilograms |
Apothecaries' Weights
Scruple
The scruple is an apothecaries' unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | scruple | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1 \cdotp 3\) | grams |
Drachm
The drachm is an apothecaries' unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | drachm | |||||||||||
| \(\ds \) | \(=\) | \(\ds 3\) | scruples | |||||||||||
| \(\ds \) | \(=\) | \(\ds 60\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 3 \cdotp 89\) | grams |
Ounce
The apothecaries' ounce is an apothecaries' unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | apothecaries' ounce | |||||||||||
| \(\ds \) | \(=\) | \(\ds 8\) | drachms | |||||||||||
| \(\ds \) | \(=\) | \(\ds 24\) | scruples | |||||||||||
| \(\ds \) | \(=\) | \(\ds 480\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1\) | troy ounce | |||||||||||
| \(\ds \) | \(=\) | \(\ds 31 \cdotp 1\) | grams |
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
Pennyweight
The pennyweight is a troy unit of mass.
| \(\ds \) | \(\) | \(\ds 1\) | pennyweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 24\) | grains | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 1 \cdotp 56\) | grams |
Ounce
| \(\ds \) | \(\) | \(\ds 1\) | troy ounce | |||||||||||
| \(\ds \) | \(=\) | \(\ds 20\) | pennyweight | |||||||||||
| \(\ds \) | \(=\) | \(\ds 480\) | grains | |||||||||||
| \(\ds \) | \(=\) | \(\ds 1\) | apothecaries' ounce | |||||||||||
| \(\ds \) | \(\approx\) | \(\ds 31 \cdotp 1\) | grams |
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 |
Talent
| \(\ds \) | \(\) | \(\ds 1\) | talent | |||||||||||
| \(\ds \) | \(=\) | \(\ds 75\) | troy pounds | |||||||||||
| \(\ds \) | \(=\) | \(\ds 900\) | troy ounces |
Also known as
The imperial or FPS system of measurement is also referred to as the British system.
Also see
- Results about imperial can be found here.
Historical Note
The imperial system was developed in Britain, and formally defined in $1824$.
It was adopted by the British Empire, and widely used in various forms in most English-speaking countries.
In the mid-$20$th century, it was officially superseded by the metric system, although is still used for various purposes.
For scientific purposes the SI system has replaced it.
Sources
- 1964: D.E. Rutherford: Classical Mechanics (3rd ed.) ... (previous) ... (next): Chapter $\text I$: Kinematics: $1$. Space and Time
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): imperial units
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): imperial units