Milli-

"Milli" redirects here. For other uses, see Milli (disambiguation).

Milli (symbol m) is a unit prefix in the metric system denoting a factor of one thousandth (10⁻³). Adopted in 1795, the prefix comes from the Latin mille, meaning one thousand (the plural is milia).

Example:

• Snow is crystalline water and is about 1 millimetre in diameter.

SI prefixes

Prefix 1000m 10n Decimal English word Since name symbol short scale long scale yotta Y  10008  1024 1000000000000000000000000  septillion  quadrillion 1991 zetta Z  10007  1021 1000000000000000000000  sextillion  thousand trillion 1991 exa E  10006  1018 1000000000000000000  quintillion  trillion 1975 peta P  10005  1015 1000000000000000  quadrillion  thousand billion 1975 tera T  10004  1012 1000000000000  trillion  billion 1960 giga G  10003  109 1000000000  billion  thousand million 1960 mega M  10002  106 1000000             million 1960 kilo k  10001  103 1000             thousand 1795 hecto h  10002/3  102 100             hundred 1795 deca da  10001/3  101 10             ten 1795  10000  100 1             one – deci d  1000−1/3  10−1 0.1             tenth 1795 centi c  1000−2/3   10−2 0.01             hundredth 1795 milli m  1000−1  10−3 0.001             thousandth 1795 micro μ  1000−2  10−6 0.000001             millionth 1960 nano n  1000−3  10−9 0.000000001  billionth  thousand millionth 1960 pico p  1000−4  10−12 0.000000000001  trillionth  billionth 1960 femto f  1000−5  10−15 0.000000000000001  quadrillionth  thousand billionth 1964 atto a  1000−6  10−18 0.000000000000000001  quintillionth  trillionth 1964 zepto z  1000−7  10−21 0.000000000000000000001  sextillionth  thousand trillionth 1991 yocto y  1000−8  10−24  0.000000000000000000000001  septillionth  quadrillionth  1991