Prefixes for SI Units

Factor

Prefix

Symbol

1024

Yotta-

Y

1021

Zetta-

Z

1018

Exa-

E

1015

Peta-

P

1012

Tera-

T

109

Giga-

G

106

Mega-

M

103

kilo-

k

102

hecto-

h

101

deka-

da

100

(unit)

(m, s, kg, K, mol, A, cd, etc.)

10−1

deci-

d

10−2

centi-

c

10−3

milli-

m

10−6

micro-

μ

10−9

nano-

n

10−12

pico-

p

10−15

femto-

f

10−18

atto-

a

10−21

zepto-

z

10−24

yocto-

y
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To change from one prefix to another, determine the difference in the numbers of the exponents. If the direction from the starting exponent to the ending exponent is down, move the decimal point to the right. If the direction is up, move the decimal point to the left.