Conversion Factors

Length
1 in = 25.4 m {Inch (in), Milimetre(mm)}
1 ft = 30.5 cm {foot(ft), Centimetre(cm)}
1 yd = 0.914 m {yard(yd), metre(m)}
1 fur = 201 m {furlong(fur), metre(m)}
1 mile = 1.61 km {mile, kilometre(km)}
1 n mile = 1852 m {International Nautical Mile(n mile), metre(m)}

Mass
1 oz = 28.3 g, 1 g = 0.0353 oz {ounce(oz), gram(g)}
1 lb = 454 g, 1 kg = 2.20 lb {pound(lb), gram(g) or kilogram(kg)}
1 stone = 6.35 kg, 1 kg = 0.157 stone {stone, kilogram(kg)}
1 ton = 1.02 t, 1 t = 0.984 {ton, tonne(t)}

Force
1 lbf = 4.45 N, 1 N = 0.225 lbf {pound force(lbf), newton(N)}
1 tonf = 9.96 kn, 1 kn = 0.100 tonf {ton force(tonf), kilonewton(kn)}

Energy
1 Btu = 1.06 KJ, 1 Kj = 0.948 Btu {British Thermal Unit(Btu), kilo joule(KJ)}
1 therm = 106 MJ, 1 MJ = 9.48 x 103 therm {therm, mega joule(MJ)}
1 kwh = 3.60 MJ {(for electrical energy), kilowatt hour(kWh)}

Power
1 hp = 0.746 kw, 1 kw = 1.34 hp {horsepower, kilowatt(kw)}

Time
1 min = 60 s {minute(min), second(s)}
1 h = 3600 s {hour(h), minute(min)}

Frequency
1 c/s = 1 Hz, 1 Hz = 1 c / s {(cycle per second(c / s), hertz(Hz) )}