International System of Units (SI)
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Base SI units
Basic Physical Quantity | SI Unit | Symbol |
---|---|---|
length | metre | m |
mass | kilogram | kg |
time | second | s |
electric current | ampere | A |
thermodynamic temperature | kelvin | K |
amount of substance | mole | mol |
luminous intensity | candela | cd |
Supplementary units
SI Unit |
Symbol | |
plane angle | radian | rad |
solid angle | steradian | sr |
Some derived SI units with special names
Physical Quantity | SI Unit | Symbol |
---|---|---|
frequency | hertz | Hz |
energy | joule | J |
force | newton | N |
power | watt | W |
electric charge | coulomb | C |
potential difference | volt | V |
resistance | ohm | Ω |
capacitance | farad | F |
conductance | siemens | S |
magnetic flux | weber | Wb |
inductance | henry | H |
magnetic flux density | tesla | T |
luminous flux | lumen | lm |
illumination | lux | lx |
Prefixes for SI units
Fraction | Prefix | Symbol | Multiple | Prefix | Symbol |
---|---|---|---|---|---|
10-1 | deci | d | 10 | deka | da |
10-2 | centi | c | 102 | hecto | h |
10-3 | milli | m | 103 | kilo | k |
10-6 | micro | μ | 106 | mega | M |
10-9 | nano | n | 109 | giga | G |
10-12 | pico | p | 1012 | tera | T |
10-15 | femto | f | 1015 | peta | P |
10-18 | atto | a | 1018 | exa | E |