SI prefix

 

Prefix		1000m	10n	Decimal	English word		Adoption[nb 1]
Name	Symbol				Short scale	Long scale
yotta	Y	10008	1024	1000000000000000000000000	septillion	quadrillion	1991
zetta	Z	10007	1021	1000000000000000000000	sextillion	thousand trillion or trilliard	1991
exa	E	10006	1018	1000000000000000000	quintillion	trillion	1975
peta	P	10005	1015	1000000000000000	quadrillion	thousand billion or billiard	1975
tera	T	10004	1012	1000000000000	trillion	billion	1960
giga	G	10003	109	1000000000	billion	thousand million or milliard	1960
mega	M	10002	106	1000000	million		1960 (1873)
kilo	k	10001	103	1000	thousand		1960 (1795)
hecto	h	10002/3	102	100	hundred		1960 (1795)
deca	da	10001/3	101	10	ten		1960 (1795)
		10000	100	1	one		–
deci	d	1000−1/3	10−1	0.1	tenth		1960 (1795)
centi	c	1000−2/3	10−2	0.01	hundredth		1960 (1795)
milli	m	1000−1	10−3	0.001	thousandth		1960 (1795)
micro	μ	1000−2	10−6	0.000001	millionth		1960 (1873)
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