Prefix Symbol Multiple
yotta Y 10 to the 24th power (septillion)
zetta Z 10 to the 21st power (sextillion)
exa E 10 to the 18th power (quintillion)
peta P 10 to the 15th power (quadrillion)
tera T 10 to the 12th power (trillion)
giga G 10 to the 9th power (billion)
mega M 10 to the 6th power (million)
kilo k 10 to the 3rd power (thousand)
hecto h 10 to the 2nd power (hundred)
deca d 10 to the 1st power (ten)
deci da 10 to the -1st power (tenth)
centi c 10 to the -2nd power (hundredth)
milli m 10 to the -3rd power (thousandth)
micro
nano n 10 to the -9th power (billionth)
pico p 10 to the -12th power (trillionth)
femto f 10 to the -15th power (quadrillionth)
atto a 10 to the -18th power (quintillionth)
zepto z 10 to the -21st power (sextillionth)
yocto y 10 to the -24th power (septillionth)
10 to the -6th power (billionth)