assert_eq(1 deg, pi / 180 * rad)
assert_eq(1 ha, 1 hm²)
assert_eq(1 L, 1 dm³)
assert_eq(1 ton, 1000 kg)
assert_eq(1 eV, 1.602176e-19 J, 1e-6 eV)
assert_eq(1 au, 149_597_870_700 meter)
assert_eq(1 bar, 10^5 Pa)
assert_eq(1 Å, 100 pm)
assert_eq(1 barn, 100 fm², 1e-5 fm²)

assert_eq(1 min, 60 s)
assert_eq(1 hour, 60 min)
assert_eq(1 week, 7 day)
assert_eq(1 day, 24 hour)
assert_eq(1 month, 730.485 hour, 0.001 hour)
assert_eq(1 gregorian_year, 365.2425 day)
assert_eq(1 julian_year, 365.25 day)
assert_eq(1 year, 1 tropical_year)

assert_eq(1 gallon, 231 inch³, 1e-5 inch³)
assert_eq(8 pint, 1 gallon)
assert_eq(2 cup, 1 pint)
assert_eq(16 tablespoon, 1 cup)
assert_eq(3 teaspoon, 1 tablespoon, 1e-5 teaspoon)
assert_eq(1 floz, 2 tablespoon)
assert_eq(1 hogshead, 63 gallon)
assert_eq(1 rod, 16.5 foot)

assert_eq(1 foot, 0.3048 meter, 1e-9 m)
assert_eq(1 yard, 0.9144 meter, 1e-9 m)
assert_eq(1 mile, 1609.344 meter, 1e-9 m)
assert_eq(1 grain, 64.79891 mg)
assert_eq(1 ounce, 28.349523125 g, 1e-6 g)
assert_eq(1 long_hundredweight, 50.80234544 kg, 1e-6 kg)
assert_eq(1 long_ton, 1016.0469088 kg, 1e-6 kg)
assert_eq(1 pound, 453.59237 gram, 1e-5 g)
assert_eq(1 gallon, 3.785_411_784 L, 1e-6 L)

assert_eq(1 imperial_fluidounce, 28.413_062_5 mL)
assert_eq(1 imperial_pint, 568.261_25 mL)
assert_eq(1 imperial_quart, 1.136_522_5 L, 1e-5 L)
assert_eq(1 imperial_gallon, 4.546_09 L, 1e-5 L)
assert_eq(1 imperial_bushel, 36.368_72 L, 1e-5 L)
assert_eq(1 imperial_fluid_drachm, 3.551_632_812_5 mL)
assert_eq(1 imperial_gill, 142.065_312_5 mL)


assert_eq(1 gauss, 100 µT)
assert_eq(1 furlong, 220 yard)

assert_eq(1 parsec, 206264 au, 1 au)
assert_eq(1 lightyear, 63241 au, 1 au)
assert_eq(1 lightyear, 0.3066 parsec, 1e-3 parsec)

assert_eq(1 knot, 1 NM/hour)

assert_eq(3 percent, 3e-2)
assert_eq(400e-6, 400 ppm, 1e-16)
assert_eq(8e-9, 8 ppb, 1e-16)
assert_eq(8e-12, 8 ppt, 1e-16)
assert_eq(8e-15, 8 ppq, 1e-16)

assert_eq(1 calorie, 4.184 J)
assert_eq(1 BTU, 1055.05585262 J)
assert_eq(1 lbf, 4.448222 N)
assert_eq(1 ozf, (4.448222 / 16.0) N, 1e-5 N)
assert_eq(60 RPM, 1 Hz)
assert_eq(1 fortnight, 2 week)
assert_eq(1 mmHg, 133.322387415 Pa, 1e-5 Pa)
assert_eq(1 PSI, 6.894757 kPa)
assert_eq(1 atm, 101_325.0 Pa)

assert_eq(1 maxwell, 1e-8 weber)
