This article is about the SI prefix. For other uses, see
Tera .
Look up tera- in Wiktionary, the free dictionary.
Tera is a unit prefix in the metric system denoting multiplication by 1012 or 1000 000 000 000 (one trillion short scale ; one billion long scale). It has the symbol T . Tera is derived from Greek word τέρας teras , meaning "monster".[1] The unit prefix was confirmed for use in the International System of Units (SI) in 1960.
Examples of its use:
Prefix
Base 1000
Base 10
Decimal
English word
Adoption[nb 1]
Name
Symbol
Short scale
Long scale
yotta
Y
10008
1024
1000 000 000 000 000 000 000 000
septillion
quadrillion
1991
zetta
Z
10007
1021
1000 000 000 000 000 000 000
sextillion
trilliard
1991
exa
E
10006
1018
1000 000 000 000 000 000
quintillion
trillion
1975
peta
P
10005
1015
1000 000 000 000 000
quadrillion
billiard
1975
tera
T
10004
1012
1000 000 000 000
trillion
billion
1960
giga
G
10003
109
1000 000 000
billion
milliard
1960
mega
M
10002
106
1000 000
million
1873
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
1873
nano
n
1000−3
10−9
0.000000 001
billionth
milliardth
1960
pico
p
1000−4
10−12
0.000000 000 001
trillionth
billionth
1960
femto
f
1000−5
10−15
0.000000 000 000 001
quadrillionth
billiardth
1964
atto
a
1000−6
10−18
0.000000 000 000 000 001
quintillionth
trillionth
1964
zepto
z
1000−7
10−21
0.000000 000 000 000 000 001
sextillionth
trilliardth
1991
yocto
y
1000−8
10−24
0.000000 000 000 000 000 000 001
septillionth
quadrillionth
1991
^ Prefixes adopted before 1960 already existed before SI. 1873 was the introduction of the CGS system .
See also [ edit ]
References [ edit ]
^ C. Upward, G. Davidson, The History of English Spelling , Wiley-Blackwell (2011)