Imperial System of Measurement

Measurement is finding a number that shows the size or amount of something.

Usually the number is in reference to some standard measurement, such as a meter or kilogram.

We can measure many different things, but most often we measure Length, Area, Volume, Mass and Time

History of Measurement

Years ago people came up with standard length measures, but they didn't all agree on one system.

The Imperial System (which uses measurements like yards, feet, pounds, ounces gallons and pints) was developed over hundreds of years in the UK, then the French developed the Metric System in 1670, which soon spread through Europe, even to England itself in 1963.

The USA uses a version of the Imperial System called "US Custoimary Units".

Length

1 inch [in]  
1 foot [ft] 12 in
1 yard [yd] 3 ft
1 mile 1760 yd
1 int nautical mile 2025.4 yd

Area

1 sq inch [in2]  
1 sq foot [ft2] 144 in2
1 sq yd [yd2] 9 ft2
1 acre 4840 yd2
1 sq mile [mile2] 640 acres

Volume/Capacity

Imperial
1 cu inch [in3]  
1 cu foot [ft3] 1,728 in3
1 fluid ounce [fl oz]  
1 pint [pt] 20 fl oz
1 gallon [gal] 8 pt

USA Measure
1 fluid ounce 1.0408 UK fl oz
1 pint (16 fl oz) 0.8327 UK pt
1 gallon 0.8327 UK gal

Mass

1 ounce [oz] 437.5 grain
1 pound [lb] 16 oz
1 stone 14 lb
1 hundredweight [cwt] 112 lb
1 long ton (UK) 20 cwt

Temperature

To convert from Celsius to Fahrenheit, first multiply by 9/5, then add 32.
To convert from Fahrenheit to Celsius, first subtract 32, then multiply by 5/9

(To find out why, visit the Temperature Conversion page)