Imperial units facts for kids
The Imperial units or the Imperial system is a collection of measurement units. An Act of Parliament in 1824 created it from traditional English units. Commonwealth countries used this system from 1824 until they changed to the metric system. The imperial system is very similar to the American system but there are some differences.
Length
| inch | link | foot | yard | pole | chain | furlong | mile | league | metre | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 inch | 1 | 25⁄198 | 1⁄12 | 1⁄36 | 1⁄198 | 1⁄792 | 1⁄7,920 | 1⁄63,360 | 1⁄190,080 | 0.0254 |
| 1 link | 7+23⁄25 | 1 | 33⁄50 | 11⁄50 | 1⁄25 | 1⁄100 | 1⁄1,000 | 1⁄8,000 | 1⁄24,000 | 0.201168 |
| 1 foot | 12 | 1+17⁄33 | 1 | 1⁄3 | 2⁄33 | 1⁄66 | 1⁄660 | 1⁄5,280 | 1⁄15,840 | 0.3048 |
| 1 yard | 36 | 4+6⁄11 | 3 | 1 | 2⁄11 | 1⁄22 | 1⁄220 | 1⁄1,760 | 1⁄5,280 | 0.9144 |
| 1 pole | 198 | 25 | 16+1⁄2 | 5+1⁄2 | 1 | 1⁄4 | 1⁄40 | 1⁄320 | 1⁄960 | 5.0292 |
| 1 chain | 792 | 100 | 66 | 22 | 4 | 1 | 1⁄10 | 1⁄80 | 1⁄240 | 20.1168 |
| 1 furlong | 7,920 | 1,000 | 660 | 220 | 40 | 10 | 1 | 1⁄8 | 1⁄24 | 201.168 |
| 1 mile | 63,360 | 8,000 | 5,280 | 1,760 | 320 | 80 | 8 | 1 | 1⁄3 | 1,609.344 |
| 1 league | 190,080 | 24,000 | 15,840 | 5,280 | 960 | 240 | 24 | 3 | 1 | 4,828.032 |
The British nautical mile used to be 6080 feet. In 1970 the UK adopted the international definition of 1852 metres.
Measures of area
| Derived | Square rods (sq poles) | Square miles | Square feet | Hectares (Metric) | Square Metres (Metric) | |
|---|---|---|---|---|---|---|
| 1 square foot | = 1 foot x 1 foot | = 0.003673095 square rods |
= 0.00000003587 square mile |
= 1 square foot | = 0.000009289257 ha | = 0.09290304 m² |
| 1 perch | = 1 rod × 1 rod | = 1 square rods | = 1⁄102400 square mile | = 272.25 square feet | = 0.002529 ha | = 25.29285264 m² |
| 1 rood | = 1 furlong × 1 rod | = 40 square rods | = 1⁄2560 square mile | = 10890 square feet | = 0.10117141056 ha | = 1011.7141056 m² |
| 1 acre | = 1 furlong × 1 chain | = 160 square rods | = 1⁄640 square mile | = 43560 square feet | = 0.40468564224 ha | = 4046.8564224 m² |
Volume
| ounce | gill | pint | quart | gallon | litre | |
|---|---|---|---|---|---|---|
| 1 (fluid) ounce | 1 | 1⁄5 | 1⁄20 | 1⁄40 | 1⁄160 | 0.028 413 |
| 1 gill | 5 | 1 | 1⁄4 | 1⁄8 | 1⁄32 | 0.142 065 |
| 1 pint | 20 | 4 | 1 | 1⁄2 | 1⁄8 | 0.568 261 |
| 1 quart | 40 | 8 | 2 | 1 | 1⁄4 | 1.136 522 |
| 1 gallon | 160 | 32 | 8 | 4 | 1 | 4.546 09 |
| 1 peck | = 2 gal | = 9.092 18 L | ||
|---|---|---|---|---|
| 1 kenning or bucket | = 2 pecks | = 4 gal | = 18.184 36 L | |
| 1 bushel | = 2 kennings | = 4 pecks | = 8 gal | = 36.368 72 L |
| 1 strike | = 2 bushels | = 16 gal | = 72.737 44 L | |
| 1 quarter or pail | = 8 bushels | = 64 gal | = 290.949 76 L | |
| 1 chaldron | = 4 quarters | = 32 bushels | = 256 gal | = 1163.799 04 L |
| 1 last | = 10 quarters | = 80 bushels | = 640 gal | = 2909.497 6 L |
| 1 firkin | = 9 gal | = 40.914 81 L | ||
|---|---|---|---|---|
| 1 kilderkin | = 2 firkin | = 18 gal | = 81.829 62 L | |
| 1 barrel | = 2 kilderkin | = 4 firkin | = 36 gal | = 163.659 24 L |
| 1 hogshead | = 3 kilderkin | = 6 firkin | = 54 gal | = 245.488 86 L |
The full table of British apothecaries’ measure is:
| 1 minim | = 0.059 193 880 208¯3 mL | ||
|---|---|---|---|
| 1 (fluid) scruple | = 20 minims | = 1.183 877 604 1¯6 mL | |
| 1 (fluid) dram or fluidram | = 3 scruples | = 60 minims | = 3.551 632 812 5 mL |
| 1 fluid ounce | = 8 drachms | = 480 minims | = 28.413 062 5 mL |
| 1 pint | = 20 ounces | = 568.261 25 mL | |
| 1 gallon | = 8 pints | = 160 ounces | = 4.546 09 L |
For a comparison to the United States customary units see the article on Comparison of the Imperial and US customary systems.
Mass and weight
| 1 grain | = 64.798 91 mg | ||
|---|---|---|---|
| 1 drachm | = 1/16 ounce | = 1/256 pound | = 1.771 845 195 312 5 g |
| 1 ounce | = 1/16 pound | = 28.349 523 125 g | |
| 1 pound | = 7000 grains | = 453.592 37 g | |
| 1 stone | = 14 pounds | = 6.350 293 18 kg | |
| 1 quarter | = 2 stone | = 28 pounds | = 12.700 586 36 kg |
| 1 hundredweight | = 4 quarters | = 112 pounds | = 50.802 345 44 kg |
| 1 ton | = 20 hundredweight | = 2240 pounds | = 1016.046 908 8 kg |
Related pages
- Jacques J. Proot's Anglo-Saxon weights & measures page.
Images for kids
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The former Weights and Measures office in Seven Sisters, London (590 Seven Sisters Road)
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Imperial standards of length 1876 in Trafalgar Square, London.
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All units of length defined by Appendix C of the NIST Handbook
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A one US gallon gas can purchased near the US-Canada border showing equivalences in imperial gallons and litres
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Imperial and metric measurements on Canadian canned goods labels. The imperial measurements often take precedence over the metric ones on labels.
