SwedeTeam Prefixes


Table 1 SI Prefixes - Base 10

Factor Prefix Symbol Ordinary Notation1 English (US2)
101 deca da 10 ten
102 hecto h 100 hundred
103 kilo k 1 000 thousand
106 mega M 1 000 000 million
109 giga G 1 000 000 000 billion2
1012 tera T 1 000 000 000 000 trillion2
1015 peta P 1 000 000 000 000 000 quadrillion2
1018 exa E 1 000 000 000 000 000 000 quintillion2
1021 zetta Z 1 000 000 000 000 000 000 000 sextillion2
1024 yotta Y 1 000 000 000 000 000 000 000 000 septillion2
         
10–1 deci d 0,1 tenth
10–2 centi c 0,01 hundredth
10–3 milli m 0,001 thousandth
10–6 micro µ 0,000 001 millionth
10–9 nano n 0,000 000 001 billionth2
10–12 pico p 0,000 000 000 001 trillionth2
10–15 femto f 0,000 000 000 000 001 quadrillionth2
10–18 atto a 0,000 000 000 000 000 001 quintillionth2
10–21 zepto z 0,000 000 000 000 000 000 001 sextillionth2
10–24 yocto y 0,000 000 000 000 000 000 000 001 septillionth2
1

Use space to separate numbers into groups of three digits - never comma or dot. See also ISO-31 and Writing Guidelines.

2 Terms like billion, trillion, etc are ambiguous. A Billion in English English differ from a Billion in US English. See also What's a Billion...?

 
The SI prefixes above refer strictly to powers of 10. They should not be used to indicate powers of 2 (for example, one kilobit represents 1000 bits and not 1024 bits).

Table 2 IEC Prefixes - Base 2 Binary

Factor Name Symbol Origin Notes
 210 kibi Ki kilobinary: (210)1 1024
 220 mebi Mi megabinary: (210) 100
 230 gibi Gi gigabinary: (210)3 1 048 576
 240 tebi Ti terabinary: (210)4 1 073 741 824
 250 pebi Pi petabinary: (210)5 1 099 511 627 776
 260 exbi Ei exabinary: (210)6 1 125 899 906 842 624

 

Examples and comparisons with SI prefixes
one kibibit  1 Kibit = 210 bit = 1024 bit
one kilobit  1 kbit = 103 bit = 1000 bit
one mebibyte  1 MiB = 220 B = 1 048 576 B
one megabyte  1 MB = 106 B = 1 000 000 B
one gibibyte  1 GiB = 230 B = 1 073 741 824 B
one gigabyte  1 GB = 109 B = 1 000 000 000 B

From physics.nist.gov/cuu/Units/binary.html retrieved 2005-11-26


 

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