Measurement Conversion Factors
* = multiply / = divide
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.
Fahrenheit (F) to Celsius (C)
Start with (F); subtract 32; multiply by 5; divide by 9; the answer is (C)Celsius (C) to Fahrenheit (F)
Start with (C); multiply by 9; divide by 5; add on 32; the answer is (F)