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Base Units

Length

  • meter (m)
  • inch (in)
  • foot (ft)
  • yard (yd)
  • mile (mi)
  • link (li)
  • rod (rd)
  • chain (ch)
  • angstrom
  • mil

Surface Area

  • sqin
  • sqft
  • sqyd
  • sqmi
  • sqrd
  • sqch
  • sqmil
  • acre
  • hectare

Volume

  • litre (l, L, lt, liter)
  • cc
  • cuin
  • cuft
  • cuyd
  • teaspoon
  • tablespoon

Liquid Volume

  • minim
  • fluiddram (fldr)
  • fluidounce (floz)
  • gill (gi)
  • cup (cp)
  • pint (pt)
  • quart (qt)
  • gallon (gal)
  • beerbarrel (bbl)
  • oilbarrel (obl)
  • hogshead
  • drop (gtt)

Angles

  • radian (rad)
  • degree (deg)
  • gradian (grad)
  • cycle
  • arcsecond (arcsec)
  • arcminute (arcmin)

Time

  • second (s, secs, seconds)
  • minute (min, mins, minutes)
  • hour (h, hr, hrs, hours)
  • day (days)
  • week (weeks)
  • month (months)
  • year (years)
  • decade (decades)
  • century (centuries)
  • millennium (millennia)

Frequency

  • hertz (Hz)

Mass

  • gram (g)
  • tonne
  • ton
  • grain (gr)
  • dram (dr)
  • ounce (oz)
  • poundmass (lbm, lb, lbs)
  • hundredweight (cwt)
  • stick
  • stone

Electric Current

  • ampere (A)

Temperature

  • kelvin (K)
  • celsius (degC)
  • fahrenheit (degF)
  • rankine (degR)

Amount of Substance

  • mole (mol)

Luminous Intensity

  • candela (cd)

Force

  • newton (N)
  • dyne (dyn)
  • poundforce (lbf)
  • kip

Energy

  • joule (J)
  • erg
  • Wh
  • BTU
  • electronvolt (eV)

Power

  • watt (W)
  • hp

Pressure

  • pascal (Pa)
  • psi
  • atm
  • torr
  • bar

Electricity and Magnetism

  • ampere (A)
  • coulomb (C)
  • watt (W)
  • volt (V)
  • ohm
  • farad (F)
  • weber (Wb)
  • tesla (T)
  • henry (H)
  • siemens (S)
  • electronvolt (eV)

Binary

  • bits (b)
  • bytes (B)
All time units are based on the Julian year, with one month being 1/12th of a Julian year, a year being one Julian year, a decade being 10 Julian years, a century being 100, and a millennium being 1000.

Prefixes

Decimal Prefixes

Binary Prefixes

Physical Constants

Universal Constants

Electromagnetic Constants

Atomic and Nuclear Constants

Physico-Chemical Constants

Adopted Values

Natural Units

The values of loschmidt and molar volume are at T = 273.15 K and p = 101.325 kPa. The value of sackur tetrode is at T = 1 K and p = 101.325 kPa.

Extended Units