Prefix Symbol Numerical Value
deca da ten
hecto h hundred
kilo k thousand
mega M million
giga G 109
tera T 1012
peta P 1015
exa E 1018
zetta Z 1021
yotta Y 1024
deci d tenth
centi c hundredth
milli m thousandth
micro µ millionth
nano n 10−9
pico p 10−12
femto f 10−15
atto a 10−18
zepto z 10−21
yocto y 10−24