SI Units

  SI Units
SI = Systm International units

Quantity, Name, Symbol

length                   

metre (meter): m

(the correct English spelling of the unit is "metre", but the variant "meter" is frequently used in the United States)

mass

kilogram: kg

time

second: s

electric current

ampere: A

thermodynamic temperature

kelvin: K

amount of substance

mole: mol

luminous intensity

candela: cd

SI Prefixes

exponent (base 10) of decimal numbers: E n = 10ⁿ

Factor           Prefix   Symbol

1024     E 24     yotta    Y

1021     E 21     zetta    Z

1018     E 18     exa      E

1015     E 15     peta     P

1012     E 12     tera     T

109      E  9     giga     G

106      E  6     mega     M

103      E  3     kilo     k

102      E  2     hecto    h

101      E  1     deca     da

10-1     E -1     deci     d

10-2     E -2     centi    c

10-3     E -3     milli    m

10-6     E -6     micro    µ

10-9     E -9     nano     n

10-12    E-12     pico     p

10-15    E-15     femto    f

10-18    E-18     atto     a

10-21    E-21     zepto    z

10-24    E-24     yocto    y