Measurement conversion factors to convert US and UK measurements to SI ( metric )  # Measurement Conversion Factors

 To convert into x = multiply / = divide acres hectares x 0.4047 acres sq. kilometres / 247 acres sq. metres x 4047 acres sq. miles / 640 barrels (oil) cu.metres / 6.29 barrels (oil) gallons (GB) x 34.97 barrels (oil) gallons (USA) x 42 barrels (oil) litres/(ers) x 159 centimetres feet / 30.48 centimetres inches / 2.54 centimetres metres / 100 centimetres millimetres x 10 cubic cm cubic inches x 0.06102 cubic cm litres/(ers) / 1000 cubic cm millilitres/(ers) x 1 cubic feet cubic inches x 1728 cubic feet cubic metres x 0.0283 cubic feet cubic yards / 27 cubic feet gallons (GB) x 6.229 cubic feet gallons (USA) x 7.481 cubic feet litres/(ers) x 28.32 cubic inches cubic cm x 16.39 cubic inches litres/(ers) x 0.01639 cubic metres cubic feet x 35.31 feet centimetres x 30.48 feet metres x 0.3048 feet yards / 3 fl.ounces (GB) fl.ounces (USA) x 0.961 fl.ounces (GB) millilitres/(ers) x 28.41 fl.ounces (USA) fl.ounces (GB) x 1.041 fl.ounces (USA) millilitres/(ers) x 29.57 gallons pints x 8 gallons (GB) cubic feet x 0.1605 gallons (GB) gallons (USA) x 1.2009 gallons (GB) litres/(ers) x 4.54609 gallons (USA) cubic feet x 0.1337 gallons (USA) gallons (GB) x 0.8327 gallons (USA) litres/(ers) x 3.785 grams kilograms / 1000 grams ounces / 28.35 hectares acres x 2.471 hectares square km / 100 hectares square metres x 10000 hectares square miles / 259 hectares square yards x 11 960 inches centimetres x 2.54 inches feet / 12 kilograms ounces x 35.3 kilograms pounds x 2.2046 kilograms tonnes / 1000 kilograms tons (GB) / 1016 kilograms tons (USA) / 907 kilometres metres x 1000 kilometres miles x 0.6214 litres/(ers) cu.inches x 61.02 litres/(ers) gallons (GB) x 0.2200 litres/(ers) gallons (USA) x 0.2642 litres/(ers) pints (GB) x 1.760 litres/(ers) pints (US liquid) x 2.113 litres/(ers)/100km MPG (GB) 282.5/ l/100km litres/(ers)/100km MPG (USA) 235.2/ l/100km metres yards / 0.9144 metres centimetres x 100 miles kilometres x 1.609 miler per gallon (GB) litres/(ers)/100km 282.5 / MPG miler per gallon (USA) litres/(ers)/100km 235.2 / MPG miles per hour km/h mph x 1.609 km/h metres/second km/h x 0.278 km/h mph km/h x 0.621 m/sec km/h m/sec x 3.6 millimetres inches / 25.4 ounces grams x 28.35 pints (GB) litres/(ers) x 0.5683 pints (GB) pints (US liquid) x 1.201 pints (US liquid) litres/(ers) x 0.4732 pints (US liquid) pints (GB) x 0.8327 pounds kilograms x 0.4536 pounds ounces x 16 square cm sq. inches x 0.1550 square feet sq. inches x 144 square feet sq. metres x 0.0929 square inches square cm x 6.4516 square inches square feet / 144 square km acres x 247 square km hectares x 100 square km square miles x 0.3861 square metres acres / 4047 square metres hectares / 10 000 square metres square feet x10.76 square metres square yards x 1.196 square miles acres x 640 square miles hectares x 259 square miles square km x 2.590 square yards square metres /1.196 tonnes kilograms x 1000 tonnes tons (GB) x 0.9842 tonnes tons (USA) x 1.1023 tons (GB) kilograms x 1016 tons (GB) tonnes x 1.016 tons (USA) kilograms x 907.2 tons (USA) tonnes x 0.9072 yards metres x 0.9144

* = multiply   / = divide

## SI Prefixes

 Factor Name Prefix

 Factor Name Prefix
 1024 yotta Y 1021 zetta Z 1018 exa E 1015 peta P 1012 tera T 109 giga G 106 mega M 103 kilo k 102 hecto h 101 deca da

 10–1 deci d 10–2 centi c 10–3 milli m 10–6 micro µ 10–9 nano n 10–12 pico p 10–15 femto f 10–18 atto a 10–21 zepto z 10–24 yocto y

Example:

1,000   metres = 1km

1,000,000    watts = 1Mw

1/1000 of a gramme (milligram) [10–3] = 1mg

Note that only the higher value prefixes (above kilo) use upper case letters.

Note: While many of the conversion factors above are exact, some involve rounding. The table is intended for domestic rather than scientific use.

Bureau International des Poids et Mesures

Temperatures

Fahrenheit (F) to Celsius (C)

```
`      Start with (C);   multiply by 9;   divide by 5;   add on 32;   the answer is (F)  `
```Approximate Equivalents: