SI base unit - SI derived unit

SI base unit - SI derived unit - Unit Converter Online

Menu

SI base unit - SI derived unit

SI units - Conversion

The International System of Units (abbreviated SI) is the modern form of the metric system. It was established in 1960, and based on the meter-kilogram-second system. The units are divided into two classes—base units and derived units. The seven base units are represented different kinds of physical quantities.

Each SI unit is represented by a symbol, rather than an abbreviation. The use of unit symbols is regulated by precise rules. In the worldwide, in spite of using different language, however, these symbols are the same. "The SI is not static but evolves to match the world's increasingly demanding requirements for measurement."

SI base unit

Name Unit symbol Quantity Quantity symbol Dimension symbol
metre m length l (a lowercase L), x, r L
kilogram kg mass m M
second S time t T
ampere A electric current I (an uppercase i) I
kelvin K thermodynamic temperature T Θ
mole mol amount of substance n N
candela cd luminous intensity Iv (an uppercase i with lowercase non-italicized v subscript) J

SI derived unit

Name Symbol Quantity Relationship with other units
hertz Gy frequency kg
becquerel Bq radioactivity (decays per unit time) 1/s
siemens S electrical conductance 1/Ω = A/V
farad F electric capacitance C/V
lumen lm luminous flux cd⋅sr
weber Wb magnetic flux J/A
gray Gy absorbed dose (of ionizing radiation) J/kg
sievert Sv equivalent dose (of ionizing radiation) J/kg
watt W power, radiant flux J/s = V⋅A
degree Celsius °C temperature relative to 273.15 K K
newton N force, weight kg⋅m/s2
lux lx illuminance lm/m2
radian rad angle m/m
steradian sr solid angle m2/m2
katal kat catalytic activity mol/s
pascal Pa pressure, stress N/m2
joule J energy, work, heat N⋅m = C⋅V = W⋅s
coulomb C electric charge or quantity of electricity s⋅A
ohm Ω electric resistance, impedance, reactance V/A
henry H inductance V⋅s/A = Wb/A
tesla T magnetic field strength V⋅s/m2 = Wb/m2 = N/(A⋅m)
volt V voltage, electrical potential difference, electromotive force W/A = J/C