Length
1 m = 100 cm = 1000 mm = 106 μm = 109nm
1 km = 1000 m = 0.6214 mi
1 m = 3.281 ft = 39.37 in
1 cm = 0.3937 in
1 in. = 2.540 cm
1 ft = 30.48 cm = 0.3048 m
1 yd = 91.44 cm
1 mi = 5280 ft = 1.609 km
1 Å = 10-10 m = 10-8 cm = 10-1 nm
1 nautical mile = 6080 ft
1 light year = 9.461 x 1015 m
1 ft = 12 in
1 in = 2.54 cm
1 μm = 10-6 m = 10-4 cm
Area
1 cm2 = 0.155 in2
1 m2 = 104 cm2 = 10.75 ft2
1 in.2 = 6.452 cm2
1 ft = 144 in2 = 0.0929 m2
Volume
1 liter = 1000 cm3 = 10-3 m3 = 0.03531 ft3 = 61.02 in3
1 ft3 = 0.02832 m3 = 28.32 liters = 7.477 gallons
1 gallon = 3.788 liters
Time
1 min = 60 s
1 h = 3600 s
1 d = 86,400 s
1 y = 365.24 d = 3.156 x 107s
Angle
1 rad = 57.30° = 180°/π
1° = 0.01745 rad = π/180 rad
1 revolution = 360° = 2π rad
1 rev/min (rpm) = 0.1047 rad/s
Speed
1 m/s = 3.281 ft/s
1 ft/s = 0.3048 m/s
1 mi/min = 60 mi/h = 88 ft/s
1 km/h = 0.2778 m/s = 0.6214 mi/h
1 mi/h = 1.466 ft/s = 0.4470 m/s = 1.609 km/h
1 furlong/fortnight = 1.662 x 10-4 m/s
Acceleration
1 m/s2 = 100 cm/s2 = 3.281 ft/s2
1 cm/s2 = 0.01 m/s2 = 0.03281 ft/s2
1 ft/s2 = 0.3048 m/s2 = 30.48 cm/s2
1 mi/h = 1.467 ft/s2
Mass
1 kg = 103 g = 0.0685 slug
1 g = 6.85 x 10-5 slug
1 slug = 14.59 kg
1 u = 1.661 x 10-27 kg
1 kg has a weight of 2.205 lb when g = 9.80 m/s2
1 kg = 2.205 lbm
1 slug = 32.17 lbm
1 lbm = 454 g1 lbm = 0.45359237 kg
Force
1 N = 105 dyn = 0.2248 lb
1 lb = 4.448 N = 4.448 x 105 dyn
1 dyn = 2.248 x 10-6 lbf
1 lbf = 4.448 N1 N = 105 dyn
1 lbf = 32.174 lbm ft/s2
Pressure
1 Pa = 1 N/m2 = 1.450 x 10-4 lb/in.2 = 0.209 lb/ft2
1 bar = 105 Pa = 0.1 MPa
1 lb/in.2 = 6895 Pa
1 lb/ft2 = 47.88 Pa
1 atm = 1.013 x 105 Pa = 1.013 bar = 14.7 lb/in.2 = 2117 lb/ft2
1 mm Hg = 1 torr = 133.3 Pa1 atm = 14.696 psia = 2116 lbf/ft2
1 atm = 101325 Pa = 14.696 lbf/in2
Energy
1 J = 107 ergs = 0.239 cal
1 cal = 4.186 J (based on 15° calorie)
1 ft-lb = 1.356 J
1 Btu = 1055 J = 252 cal = 778 ft-lb
1 eV = 1.602 x 10-19 J
1 kWh = 3.600 x 106 J
1 ft(lbf) = 1.356 J
1 kW(h) = 3413 Btu
1 hp(h) = 2545 Btu1 Btu = 252 cal
1 Btu = 778 ft(lbf)
Mass-Energy Equivalence
1 kg ↔ 8.988 x 1016 J
1 u ↔ 931.5 MeV
1 eV ↔ 1.074 x 10-9 u
Power
1 W = 1 J/s
1 hp = 746 W = 550 ft-lb/s
1 Btu/h = 0.293 W
Related
All about the background of British-American system of units