From Wikipedia, the free encyclopedia - View original article

Jump to: navigation, search

Tera is a unit prefix in the metric system denoting multiplication by 1012 or 1000000000000. It has the symbol T. Tera is derived from Ancient Greek τέρας (teras), meaning “monster”. The prefix tera was confirmed for use in the SI in 1960.

Metric prefixes
PrefixSymbol1000m10nDecimalEnglish word[n 1]Since[n 2]
yottaY 10008 10241000000000000000000000000septillion1991
zettaZ 10007 10211000000000000000000000sextillion1991
exaE 10006 10181000000000000000000quintillion1975
petaP 10005 10151000000000000000quadrillion1975
teraT 10004 10121000000000000trillion1960
gigaG 10003 1091000000000billion1960
megaM 10002 1061000000million1960
kilok 10001 1031000thousand1795
hectoh 10002/3 102100hundred1795
decada 10001/3 10110ten1795
 10000 1001one
decid 1000−1/3 10−10.1tenth1795
centic 1000−2/3  10−20.01hundredth1795
millim 1000−1 10−30.001thousandth1795
microµ 1000−2 10−60.000001millionth1960
nanon 1000−3 10−90.000000001billionth1960
picop 1000−4 10−120.000000000001trillionth1960
femtof 1000−5 10−150.000000000000001quadrillionth1964
attoa 1000−6 10−180.000000000000000001quintillionth1964
zeptoz 1000−7 10−210.000000000000000000001sextillionth1991
yoctoy 1000−8 10−24 0.000000000000000000000001septillionth1991
  1. ^ This table uses the short scale.
  2. ^ The metric system was introduced in 1795 with six prefixes. The other dates relate to recognition by a resolution of the CGPM.

See also[edit]