Micro

This article is about the 'micro-' prefix. Micro is also a semi-obsolete term for a microcomputer, as well as being slang for micromanagement in real-time strategy games.

micro- is a SI prefix in the SI system of units denoting a factor of 10⁻⁶ (one millionth). The symbol for it is the micro sign (µ). In circumstances where only the latin alphabet is available, it is customarily written using the letter u. E.g. um for µm, or uV for µV. Occasionally, micrograms are written as mcg.

Confirmed in 1960, the prefix comes from the Greek μικρός (transliterated: mikros), meaning small.

More generally, the prefix means "very small".

SI prefixes

10n	Prefix	Symbol	Short scale	Long scale	Decimal equivalent
1024	yotta	Y	Septillion	Quadrillion	1 000 000 000 000 000 000 000 000
1021	zetta	Z	Sextillion	Trilliard (thousand trillion)	1 000 000 000 000 000 000 000
1018	exa	E	Quintillion	Trillion	1 000 000 000 000 000 000
1015	peta	P	Quadrillion	Billiard (thousand billion)	1 000 000 000 000 000
1012	tera	T	Trillion	Billion	1 000 000 000 000
109	giga	G	Billion	Milliard (thousand million)	1 000 000 000
106	mega	M	Million		1 000 000
103	kilo	k	Thousand		1 000
102	hecto	h	Hundred		100
101	deca, deka	da	Ten		10
100	none	none	One		1
10−1	deci	d	Tenth		0.1
10−2	centi	c	Hundredth		0.01
10−3	milli	m	Thousandth		0.001
10−6	micro	µ (u)	Millionth		0.000 001
10−9	nano	n	Billionth	Milliardth	0.000 000 001
10−12	pico	p	Trillionth	Billionth	0.000 000 000 001
10−15	femto	f	Quadrillionth	Billiardth	0.000 000 000 000 001
10−18	atto	a	Quintillionth	Trillionth	0.000 000 000 000 000 001
10−21	zepto	z	Sextillionth	Trilliardth	0.000 000 000 000 000 000 001
10−24	yocto	y	Septillionth	Quadrillionth	0.000 000 000 000 000 000 000 001

See also

• SI

The content of this page is retrieved from http://en.wikipedia.org/wiki/Micro under GFDL