Hệ thống đơn vị đo lường (SI)

Length

meter

m

Mass kilogram

kilogram

kg

Time

second

s

Electrical current

ampere

A

Temperature

kelvin

K

Luminous intensity

candela

cd

Amount of substance

mole

mol

Quantity

Unit

Symbol

Expressed in other SI units

frequency

hertz

Hz

s^-1

force

newton

N

kg x m x s^-2

pressure / mechanical stress

pascal

Pa

N / m²

energy / work

joule

J

N x m

power

watt

W

J / s

electric quantity / charge

coulomb

C

A x s

electric voltage

volt

V

W / A

capacitance

farad

F

C / V

resistance

ohm

Ω

V / A

conductivity

siemens

S

A / V

magnetic flux

weber

Wb

V x s

magnetic flux density

tesla

T

Wb / m²

inductance

henry

H

Wb / A

luminous flux

lumen

lm

Cd x sr

light

lux

lx

Lm / m²

angle

radian

rad

m / m

solid angle

steradian

sr

m² / m²

Quantity

Unit

Symbol

Remark

volume

liter

l

1 l = 1 dm³

time

minute

min

1 min = 60 s

time

hour

h

1 h = 60 min

mass

metric ton

t

1 t = 1.000 kg

pressure

bar

bar

1 bar = 105 Pa

plane angle

degree

.°

1° = π/180 rad

plane angle

minute

.'

1' = 1°/60

plane angle

second

."

1" = 1'/60

Power

Prefix

Designation

Prefix

Symbol

Example

Symbol

1012

tera

T

1 terajoule

1 TJ

109

giga

G

1 gigahertz

1 GHz

106

mega

M

1 megawatt

1 MW

103

kilo

k

1 kilometer

1 km

102

hecto

h

1 hectoliter

1 hl

101

deca

da

1 decalumen

1 dalm

10-1

deci

d

1 decibel

1 dB

10-2

centi

c

1 centimeter

1 cm

10-3

milli

m

1 milligram

1 mg

10-6

micro

µ

1 micrometer

1 µm

10-9

nano

N

1 nanohenry

1 nH

10-12

pico

p

1 picofarad

1 pF

10-15

femto

f

1 femtometer

1 fm

10-18

atto

a

1 attosecond

1 as