Peta-

This article is about the SI prefix. For other uses, see Peta (disambiguation).

Peta is a unit prefix in the metric system denoting multiplication by 10¹⁵ (1000000000000000). It was adopted in the International System of Units in 1975, and has the symbol P.

Peta is derived from the Greek πέντε, meaning "five". It denotes the fifth power of 1000 (1000⁵). It is similar to the prefix penta ("five"), but without the letter n (on the analogy of the prefix tera (from the Greek for "monster") for 1000⁴ looking like tetra- ("four") with a letter missing).

Examples:

• 1 petametre = 10¹⁵ metres
• 1 petasecond = 10¹⁵ seconds
• 1 petabyte = 10¹⁵ bytes
• the mass–energy equivalence is 89.9 PJ/kg
• 1 light-year = 9.461 Pm

Metric prefixes

Prefix Symbol 1000m 10n Decimal English word Since yotta Y  10008  1024 1000000000000000000000000 septillion 1991 zetta Z  10007  1021 1000000000000000000000 sextillion 1991 exa E  10006  1018 1000000000000000000 quintillion 1975 peta P  10005  1015 1000000000000000 quadrillion 1975 tera T  10004  1012 1000000000000 trillion 1960 giga G  10003  109 1000000000 billion 1960 mega M  10002  106 1000000 million 1960 kilo k  10001  103 1000 thousand 1795 hecto h  10002/3  102 100 hundred 1795 deca da  10001/3  101 10 ten 1795  10000  100 1 one – deci d  1000−1/3  10−1 0.1 tenth 1795 centi c  1000−2/3   10−2 0.01 hundredth 1795 milli m  1000−1  10−3 0.001 thousandth 1795 micro µ  1000−2  10−6 0.000001 millionth 1960 nano n  1000−3  10−9 0.000000001 billionth 1960 pico p  1000−4  10−12 0.000000000001 trillionth 1960 femto f  1000−5  10−15 0.000000000000001 quadrillionth 1964 atto a  1000−6  10−18 0.000000000000000001 quintillionth 1964 zepto z  1000−7  10−21 0.000000000000000000001 sextillionth 1991 yocto y  1000−8  10−24  0.000000000000000000000001 septillionth 1991

See also

• Binary prefix

External links

• BIPM website