Length:
  Å: value/10000000000r
  thou, mil, milli-inch: value*0.0000254r
  inch, in, ": value*0.0254r
  feet, ft, ': value*0.304r
  yard, yd: value*0.9144r
  mile, mi: value*1609.344r
  寸: value/33r
  尺: value*0.30303r
  鯨尺: value*0.37879r
  丈: value*3.0303r
  間: value*1.818r
  町, 丁: value*109.09091r
  里: value*3927.273r
  天文単位, astronomical-unit, AU: value*149597870700r
  光年, light-year, ly: value*9460730472580800r
  パーセク, parsec, pc: value*3.085677581e16.rationalize
  海里, nautical-mile: value*1852r

Weight:
  g, gram: value/1000r
  ton: value/0.001r
  grain, gr: value/15432.358352941r
  dram, dr: value/564.38339119329r
  ounce, oz: value/35.27396194958r
  pound, lb: value/2.2046226218488r
  stone, st: value*6.35029318r
  quarter: value*12.70058636r
  short-ton, sh-tn, s.t.: value*907.18474r
  分: value/2666.6666666667r
  匁: value/266.66666666667r
  百目: value/2.6666666666667r
  斤: value/1.6666666666667r

Time:
  Planck-time, tp: value*5.39116e-44.rationalize
  au: value*4.1341373345192e+16.rationalize
  min: value*60r
  hour: value*3600r
  day: value*86400r
  week: value*604800r
  month: value*2.628e+6
  year: value*31535965.4396976r
  century: value*3153600000r

Tempreture:
  K: value
  °C, degree, Celsius: value+272.15r
  °F, Fahrenheit: value*0.5555555555555556r+255.37222222222223r
  °R, Rankine scale: value/1.8r

Area:
  are, a: value*100r
  ha: value*10000r
  sq-in, in2: value*0.00064516r
  sq-ft, ft2: value*0.09290304r
  sq-yd, yd2: value*0.83612736r
  rood, ro: value*1011.7141056r
  acre, ac: value*4046.8564224r
  sq-mi, mi2: value*2589988.110336r
  坪: value*3.3057851239669r
  畝: value*99.173553719008r
  反: value*991.73553719008r
  町: value*9917.3553719008r

Volume:
  ml: value/1000000r
  cl: value/100000r
  dl: value/10000r
  l: value/1000r
  小さじ: value*5.0e-6.rationalize
  大さじ: value*1.5e-5.rationalize
  cc: value*1.0e-6.rationalize
  cu-in, in3: value*1.6387064e-5.rationalize
  cu-ft, ft3: value*0.028316846592r
  ac-ft: value*1233.4818375475r
  U.S.fluid-gallon, gallon, gal, U.S.gal, USG: value*0.003785411784r
  Imperial-gallon, imp.gal: value*0.00454609r
  Winchester-bushel, bushel, bsh., bu: value*0.03523907016688r
  us-fluid-once, fl-oz: value*2.84130625e-5.rationalize
  uk-fluid-ounce: value*2.95735295625e-5.rationalize
  us-gill, gi: value*0.00011829411825r
  uk-gill, uk-gi: value*0.0001420653125r
  us-pint, pt: value*0.000473176473r
  uk-pint, uk-pt: value*0.00056826125r
  us-quart, qt: value*0.000946352946r
  uk-quart, uk-qt: value*0.0011365225r
  us-barrel, bbl: value*0.119240471196r
  uk-barrel, uk-bbl: value*0.16365924r
  勺: value*1.8039068369647e-5.rationalize
  合: value*0.00018039068369647r
  升: value*0.0018039068369647r
  斗: value*0.018039068369647r
  石: value*0.18039068369647r

Power:
  dyn: value/100000r
  N: value
  kgf: value/0.10197162129779r
  lbf: value/0.22480894309971r
  pdl: value/7.2330138512099r

Pressure, Stress:
  N/mm2: value*1e-06.rationalize
  bar: value*100000r
  atm: value*101325r
  at: value*98066.5r
  kgf/cm2: value/1.0197162129779e-05.rationalize
  mmH2O: value*9.80665r
  cmH2O: value*98.0665r
  mmH2O(3.98°C): value*9.80638r
  cmH2O(3.98°C): value*98.0638r
  mmHg: value*133.322387415r
  inHg: value*3386.388640341r
  torr: value*133.32236842105r
  psi: value*6894.7572931684r

Electric power:
  mW: value/1000000r
  W: value/1000r
  kW: value
  dBm: value/60r
  kgfm/s: value/101.97162129779r
  PS: value/1.3596216173039r
  HP: value/1.341022089595r
  ft.lbf/s: value/737.56214927727r
  cal/s: value/238.8458966275r
  kcal/s: value/0.2388458966275r
  BTU/s: value/0.94781712031332r

Energy, Work, Heat:
  erg: value/10000000r
  kWh: value/2.7777777777778e-07
  calth: value/0.23900573613767r
  kcalth: value/2.3900573613767e-04.rationalize
  calIT: value/0.2388458966275r
  kcalIT: value/2.388458966275e-04.rationalize
  eV: value/6.2415094796077e+18.rationalize
  BTU: value/9.4781712031332e-04.rationalize
  ftlbf: value/0.73756214945755r
  ftpdl: value/23.730360457056r
  atm: value/0.0098692326671601r

Speed, Velocity:
  fps: value/3.2808398950131r
  fpm: value/196.85039370079r
  fph: value/11811.023622047r
  mps: value/0.00062137119223733r
  mpm: value/0.03728227153424r
  mph: value/2.2369362920544r
  kn: value/1.9438444924406r
  Mach: value/0.0029411764705882r

Acceleration:
  km/h/s: value/3.6r
  Gal: value/100r
  fps2: value/3.2808398950131r
  fpm/s: value/196.85039370079r
  fph/s: value/11811.023622047r
  mps2: value/6.2137119223733e-04.rationalize
  mpm/s: value/0.03728227153424r
  mph/s: value/2.2369362920544r
  kn/s: value/1.9438444924406r
  G: value/0.10197162129779r

Angle:
  °: value
  ′: value/60r
  ″: value/3,600r
  grad: value/1.1111111111111r
  rad: value/0.017453292519943r
  mil: value/17.777777777778r
  /%: value/1.7455064928218r
  ‰: value/17.455064928218r

Viscosity:
  poise: value*10
  cpoise: value*1000
  (kg/m)*h: value*3600
  (lb/ft)*s: value*0.671969