The prefixes for the creation of decimal multiples and parts of SI units are:
Factor | Name | Symbol | Factor | Name | Symbol |
1024 | yotta | Y | 10-1 | deci | d |
1021 | zetta | Z | 10–2 | centi | c |
1018 | exa | E | 10-3 | milli | m |
1015 | peta | P | 10–6 | micro | µ |
1012 | tera | T | 10-9 | nano | n |
109 | giga | G | 10-12 | pico | p |
106 | mega | M | 10-15 | femto | f |
103 | kilo | k | 10-18 | atto | a |
102 | hecto | h | 10-21 | zepto | z |
101 | deca | da | 10-24 | yocto | y |
Remarks
Symbols of prefixes are placed before the symbol of the unit without a blank. Combinations of prefixes shall not be used. For 107 joule one writes 10 MJ and not 1 daMJ. With powers of symbols before units the prefix joins in the power raising: 1 cm2 = (10-2 m)2 = 10-4 m2 and not 10-2 m2.
Multiples and parts of the basic unit kilogram are created by taking the gram (=10-3 kg) as a basis. So 10-6 kg = 1 mg and not 1 μkg.
