First you need the basics to understand the metric system.

The metric system is based on a decimal system (ie:powers of ten). Therefore, it simplifies calculations by using a set of prefixes shown in the table below.

Multiplication Factor

Prefix

Symbol

U.S Name

1,000,000,000 = 10 9

giga

G

billion

1,000,000 = 10 6

mega

M

million

1,000 = 10 3

kilo

k

thousand

100 = 10 2

hecto

h

hundred

10 = 10 1

deca

da

ten

1 = 1

one

0.1 - 10 -1

deci

d

tenth

0.01 = 10 -2

centi

c

hundredth

0.001 = 10 -3

mili

m

thousandth

0.000001 = 10 -6

micro

µ

millionth

0.000000001 = 10 -9

nano

n

billionth

Symbols must be written exactly as shown in the tables. Do not change the case, or add an "s" for the plural, or use abbreviations, or write a period after a symbol (unless it ends a sentence).

The symbols (not abbreviations) for SI units are the same all over the world, regardless of the local language spoken.