Metric Decimal Prefixes

Rules governing use of prefixes:

1. Prefixes are generally used to maintain numerical values between 0.1 and 100
2. Prefixes are generally used for powers of 3 (e.g. kilo for 10³). Use of hecto, deca, deci and centi should generally be avoided except when dealing with small areas or volumes.

Prefix	Symbol	Multiplication Factor	10n
exa	E	1 000 000 000 000 000 000	1018
peta	P	1 000 000 000 000 000	1015
tera	T	1 000 000 000 000	1012
giga	G	1 000 000 000	109
mega	M	1 000 000	106
kilo	K	1 000	103
hecto	h	100	102
deca	da	10	101
		1	100
deci	d	0.1	10-1
centi	c	0.01	10-2
milli	m	0.001	10-3
micro	µ	0.000 001	10-6
nano	n	0.000 000 001	10-9
pico	p	0.000 000 000 001	10-12
femto	f	0.000 000 000 000 001	10-15
atto	a	0.000 000 000 000 000 001	10-18