SI units

While many combinations of the base units of the SI system have specific names, those for many distinct purposes do not, e.g. the ampere·second is called the coulomb, but the metre per second squared, despite its common occurrence for acceleration, has no special name. The SI units for realms of measurement, as defined by the CGPMs, are by subject as follows, showing for each the relevant powers of base units (and any exceptional factor counted).

• absorbed dose, kerma, specific energy (imparted): J·kg^-1 = Gy = gray = m²·s^-2;
• absorbed dose rate: Gy·s^-1 = (m²·s^-2)·s¹ = m²·s^-3;
• acceleration: m·s^-2;
• activity of a radionuclide: (disintegrations)·s^-1 = Bq = becquerel = s^-1;
• amount of substance: mol = mole, a base unit;
• angular acceleration: = rad·s^-2 = (m¹·m^-1)·s^-2 = s^-2;
• angular speed: = rad·s^-1 = (m¹·m^-1)·s^-1 = s^-1;
• area: = m², also a = are = 100 m²;
• capacitance: C·V^-1 = F = farad = (s·A)·(m²·kg·s^-3·A^-1)^-1   = m^-2·kg^-1·s⁴·A²;
• catalytic activity: mol·s^-1 = kat = katal = s^-1·mol;
• catalytic (activity) concentration: kat·m^-3 = (s^-1·mol)·m^-3  = m^-3·s^-1·mol;
• dose equivalent, organ equivalent dose: J·kg^-1 = Sv = sievert = m²·s^-2 (see Sievert for qualified variants);
• dynamic viscosity: N·m·s^-1 = (m·kg·s^-2)·m·s^-1 = m^-1·kg·s^-1;
• electric current density: A·m^-2 = m^-2·A;
• electric charge: see quantity of electricity;
• electric charge density: C·m^-3 = (A·s)·m^-3 = m^-3·s·A;
• electric conductance: Ω^-1 = V^-1·A = W^-1·A² = S = siemens = (m²·kg·s^-3·A^-1)^-1·A = m^-2·kg^-1·s³·A²;
• electric current strength: A = ampere, a base unit;
• electric field strength: V·m^-1 = (m²·kg·s^-3·A^-1)·m = m·kg·s^-3·A^-1;
• electric flux density: C·m^-2 = (A·s)·m^-2 = m^-2·s·A;
• electric potential difference, electromotive force, voltage: W·A^-1 = V = volt = (m²·kg·s^-3)·A^-1 = m²·kg·s^-3·A^-1;
• electric resistance: V·A^-1 = W·A^-2 = Ω = ohm = (m²·kg·s^-3·A^-1)·A^-1 = m²·kg·s^-3·A^-2;
• electric resistivity: Ω·m²·m^-1 = (m²·kg·s^-3·A^-2)·m²·m^-1 = m³·kg·s^-3·A^-2;
• electricity (quantity of): see quantity of electricity;
• electromotive force: see electric potential difference;
• energy, work, quantity of heat: N·m = J = joule = (m·kg·s^-2)·m = m²·kg·s^-2;
• energy density: J·m^-3 = (m²·kg·s^-2)·m^-3 = m^-1·kg·s^-2;
• entropy, heat capacity: J·K^-1 = (m²·kg·s^-2)·K^-1 = m²·kg·s^-2·K^-1;
• exposure to X- or gamma rays: C·kg^-1 = (S·A)·kg^-1 = kg^-1·s·A;
• force: kg·m·s^-2 = N = newton = m·kg·s^-2;
• frequency: (cycles)·s^-1 = Hz = hertz = s^-1;
• heat capacity: see entropy;
• heat (quantity of): see energy;
• heat-flux density, irradiance: W·m^-2 = (m²·kg·s^-3)·m^-2 = kg·s^-3;
• illuminance: lm·m^-2 = lx = lux = m^-2·cd;
• inductance: Wb·A^-1 = H = henry = (m²·kg·s^-2·A^-1)·A^-1 = m²·kg·s^-2·A^-2;
• irradiance: see heat-flux density;
• kerma: see absorbed dose
• kinematic viscosity: = m²·s^-1;
• length: m = metre, a base unit;
• light (quantity of): see quantity of light;
• luminous flux: lm = lumen = cd·sr = cd·(m²·m^-2) = cd;
• luminous intensity: cd = candela, a base unit;
• magnetic field strength: A·m^-1 = m^-1·A;
• magnetic flux: V·s = Wb = weber = (m²·kg·s^-3·A^-1)·s = m²·kg·s^-2·A^-1;
• magnetic flux density: Wb·m^-2 = T = tesla = (m²·kg·s^-2·A^-1)·m^-2 = kg·s^-2·A^-1;
• mass: kg = kilogram, a base unit;
• mass density: kg·m^-3 = m^-3·kg;
• molar energy: J·mol^-1 = (m²·kg·s^-2)·mol^-1 = m²·kg·s^-2·mol^-1;
• molar entropy, molar heat capacity: J·(mol·K)^-1 = (m²·kg·s^-2)·(mol·K)^-1 = m²·kg·s^-2·K^-1·mol^-1;
• moment of force: N·m = (m·kg·s^-2)·m = m²·kg·s^-2;
• organ equivalent dose: see dose equivalent;
• permeability: H·m^-1 = (m²·kg·s^-2·A^-2)·m^-1 = m·kg·s^-2·A^-2;
• permittivity: F·m^-1 = (m^-2·kg^-1·s⁴·A²)·m^-1 = m^-3·kg^-1·s⁴·A²;
• plane angle: rad = radian, a supplementary unit prior to 1980, now = m¹·m^-1, so dimensionless;
• potential difference = electromotive force;
• power, radiant flux: J·s^-1 = W = watt = (m²·kg·s^-2)·s^-1 = m²·kg·s^-3;
• pressure, stress: N·m^-2 = Pa = pascal = (m·kg·s^-2)·m^-2 = m^-1·kg·s^-2
• quantity of electricity, electric charge: A·s = C = coulomb = s·A;
• quantity of heat: see energy;
• quantity of light: lm·s = cd·s = s·cd;
• radiance: W·m^-2·sr^-1 = (m²·kg·s^-3)·m^-2·(m²·m^-2)^-1 = kg·s^-3;
• radiant flux: see power;
• radiant intensity: W·sr^-1 = (m²·kg·s^-3)·(m²·m^-2)^-1 = m²·kg·s^-3;
• solid angle: sr = steradian, a supplementary unit prior to 1980, now = m²·m^-2, so dimensionless;
• specific energy: J·kg^-1 = (m²·kg·s^-2)·kg^-1 = m²·s^-2;
• specific energy (imparted); see absorbed dose
• specific entropy, specific heat capacity: J·(kg·K)^-1 = (m²·kg·s^-2)·(kg·K)^-1 = m²·s^-2·K^-1;
• speed: = m·s^-1;
• stress: see pressure;
• surface tension: N·m^-1 = (m·kg·s^-2)·m^-1 = kg·s^-2;
• temperature: K = kelvin, a base unit, also °C = degree Celsius = K;
• thermal conductivity: W·(m·K)^-1 = (m·kg·s^-3)·K^-1;
• thermodynamic temperature: K = kelvin, a base unit;
• time: s = second, a base unit;
• velocity; see speed;
• voltage; see electric potential difference;
• volume: cu-metre = m³;
• wave number: waves per metre = (wave)m^-1;
• work; see energy.

In descending order of the successive powers of the base units these are shown in Table 51.

An internationally agreed coherent system of units derived from the metric system. The basic units are the metre (m), kilogram (kg), ampere (A), Kelvin (K), mole (mol), and candela (cd). Derived units that are important in sports science include the newton (N), joule (Q), watt (W), and pascal (P).