Mass

1 kg = 2.2046 lbm
1 lbm = 0.4536 kg

Density

1 kg/m^3 = 0.06243 lbm/ft^3
1 lbm/ft^3 = 16.02 kg/m^3

Force

1 N = 0.2248 lbf
1 lbf = 4.448 N

Length

1 m = 3.2810 ft
1 ft = 0.3048 m

Temperature

F = C * 1.8 + 32
F = R - 460
C = (F - 32) / 1.8
C = K - 273

Pressure

1 atm = 14.696 psi
1 psi = 0.068 atm

Volume

1 m^3 = 35.32 ft^3
1 ft^3 = 0.0283 m^3

Energy, Work, Heat

1 kJ = 0.948 Btu
1 Btu = 1.055 kJ
1 Btu = 778 lbf*ft
1 kWhr = 3,412 Btu

Power

1 kW = 56.91 Btu/min
1 Btu/min = 778 lbf*ft/min
1 kW = 1.341 HP
1 HP = 550 lbf*ft/s