length:
  m  metre (also: meter, meters, metres)
  km  kilometre (also: kilometer, kilometers, kilometres)
  cm  centimetre (also: centimeter, centimeters)
  mm  millimetre (also: millimeter, millimeters)
  um  micrometre (also: µm, μm, micron, micrometer)
  nm  nanometre (also: nanometer)
  in  inch (international) (also: inch, inches, ")
  ft  foot (international) (also: foot, feet, ')
  yd  yard (also: yard, yards)
  mi  mile (international statute) (also: mile, miles)
  nmi  nautical mile (also: nautical_mile, NM)
  mil  mil (thou) (also: thou)
  au  astronomical unit (IAU 2012, exact) (also: AU)
  ly  light-year (Julian year, exact) (also: lightyear, light_year)
mass:
  kg  kilogram (also: kilogram, kilograms, kilo)
  g  gram (also: gram, grams)
  mg  milligram (also: milligram)
  ug  microgram (also: µg, μg, mcg, microgram)
  t  tonne (metric ton) (also: tonne, tonnes, metric_ton)
  lb  pound (avoirdupois) (also: lbs, pound, pounds)
  oz  ounce (avoirdupois) (also: ounce, ounces)
  ozt  troy ounce (also: troy_ounce)
  st  stone (also: stone)
  ton_us  short ton (US) (also: short_ton)
  ton_uk  long ton (UK) (also: long_ton)
  ct  carat (metric) (also: carat)
  gr  grain (also: grain)
volume:
  m3  cubic metre (also: m^3, cubic_meter)
  l  litre (also: L, liter, litre, liters, litres)
  ml  millilitre (also: mL, milliliter, cc)
  cl  centilitre (also: cL)
  dl  decilitre (also: dL)
  cm3  cubic centimetre (also: cm^3)
  in3  cubic inch (also: in^3, cubic_inch)
  ft3  cubic foot (also: ft^3, cubic_foot)
  gal  US gallon (231 in^3) (also: gallon, gallons, gal_us)
  qt  US liquid quart (also: quart, qt_us)
  pt  US liquid pint (also: pint, pt_us)
  cup  US customary cup (236.5882365 mL) (also: cups, cup_us)
  cup_metric  metric cup (250 mL)
  floz  US fluid ounce (also: fl_oz, floz_us, fluid_ounce)
  tbsp  US tablespoon (also: tablespoon)
  tsp  US teaspoon (also: teaspoon)
  gal_imp  imperial gallon (4.54609 L) (also: imperial_gallon, gal_uk)
  qt_imp  imperial quart (also: qt_uk)
  pt_imp  imperial pint (also: pt_uk)
  floz_imp  imperial fluid ounce (also: floz_uk)
  bbl  oil barrel (42 US gallons) (also: barrel)
temperature:
  K  kelvin (also: kelvin, degK)
  C  degree Celsius (also: °C, celsius, degC, ℃)
  F  degree Fahrenheit (also: °F, fahrenheit, degF, ℉)
  R  degree Rankine (also: °R, rankine, degR)
temperature difference:
  dK  kelvin (difference) (also: delta_K)
  dC  Celsius degree (difference) (also: delta_C)
  dF  Fahrenheit degree (difference) (also: delta_F)
pressure:
  Pa  pascal (also: pascal)
  hPa  hectopascal
  kPa  kilopascal
  MPa  megapascal
  bar  bar
  mbar  millibar (also: millibar)
  atm  standard atmosphere
  at  technical atmosphere (kgf/cm^2)
  psi  pound-force per square inch (also: lbf/in2)
  ksi  kilopound per square inch
  mmHg  millimetre of mercury (conventional)
  inHg  inch of mercury (conventional)
  torr  torr (also: Torr)
energy:
  J  joule (also: joule, joules)
  kJ  kilojoule
  MJ  megajoule
  GJ  gigajoule
  Wh  watt-hour
  kWh  kilowatt-hour
  MWh  megawatt-hour
  cal  thermochemical calorie (4.184 J)
  kcal  kilocalorie (thermochemical, = food Calorie)
  cal_it  International Table calorie (4.1868 J)
  eV  electronvolt (exact)
  keV  kiloelectronvolt
  MeV  megaelectronvolt
  BTU  British thermal unit (International Table) (also: btu, Btu)
  erg  erg
  ftlbf  foot-pound force (also: ft_lbf)
power:
  W  watt (also: watt, watts)
  mW  milliwatt
  kW  kilowatt
  MW  megawatt
  GW  gigawatt
  hp  mechanical horsepower (550 ft*lbf/s) (also: horsepower)
  PS  metric horsepower (PS) (also: hp_metric, cv)
  BTU/h  BTU per hour (also: btu_h, BTUh)
area:
  m2  square metre (also: m^2, sqm)
  km2  square kilometre (also: km^2)
  cm2  square centimetre (also: cm^2)
  mm2  square millimetre (also: mm^2)
  ha  hectare (also: hectare)
  are  are
  acre  acre (international foot) (also: acres, ac)
  ft2  square foot (also: ft^2, sqft)
  in2  square inch (also: in^2)
  yd2  square yard (also: yd^2)
  mi2  square mile (also: mi^2)
speed:
  m/s  metre per second (also: mps, m_s)
  km/h  kilometre per hour (also: kmh, kph, km_h)
  mph  mile per hour (also: mi/h)
  kn  knot (also: knot, knots, kt)
  ft/s  foot per second (also: fps, ft_s)
force:
  N  newton (also: newton)
  kN  kilonewton
  lbf  pound-force
  kgf  kilogram-force (also: kp)
  dyn  dyne
frequency:
  Hz  hertz
  kHz  kilohertz
  MHz  megahertz
  GHz  gigahertz
  rpm  revolutions per minute (also: RPM)
time:
  s  second (also: sec, second, seconds)
  ms  millisecond
  us  microsecond (also: µs, μs)
  ns  nanosecond
  min  minute (also: minute, minutes)
  h  hour (also: hr, hour, hours)
  d  day (86400 s) (also: day, days)
  week  week (also: weeks, wk)
data:
  bit  bit (also: bits)
  byte  byte (8 bits) (also: B, bytes, octet)
  kB  kB (10^3 bytes)
  kbit  kbit (10^3 bits)
  KiB  KiB (2^10 bytes)
  Kibit  Kibit (2^10 bits)
  MB  MB (10^6 bytes)
  Mbit  Mbit (10^6 bits)
  MiB  MiB (2^20 bytes)
  Mibit  Mibit (2^20 bits)
  GB  GB (10^9 bytes)
  Gbit  Gbit (10^9 bits)
  GiB  GiB (2^30 bytes)
  Gibit  Gibit (2^30 bits)
  TB  TB (10^12 bytes)
  Tbit  Tbit (10^12 bits)
  TiB  TiB (2^40 bytes)
  Tibit  Tibit (2^40 bits)
  PB  PB (10^15 bytes)
  Pbit  Pbit (10^15 bits)
  PiB  PiB (2^50 bytes)
  Pibit  Pibit (2^50 bits)
  EB  EB (10^18 bytes)
  Ebit  Ebit (10^18 bits)
  EiB  EiB (2^60 bytes)
  Eibit  Eibit (2^60 bits)
fuel economy:
  km/l  kilometres per litre (also: kmpl, km_l)
  mpg  miles per US gallon (also: mpg_us)
  mpg_imp  miles per imperial gallon (also: mpg_uk)
  l/100km  litres per 100 km (inverse scale) (also: L/100km, l_100km)

Symbols are case-sensitive (MB megabyte, Mbit megabit, mW milliwatt, MW megawatt). Ambiguous inputs such as 'ton' or 'mb' are refused with the alternatives.
# type: computed