Units of Measurement

The information below shows imperial to SI unit conversions

for the units of measurement most commonly used in the

Handbook. SI units are used throughout with, where appropriate, imperial units reported in parentheses.

Area

1 square inch (in2

) = 6.4516  10–4 square meter (m2

)

1 square foot (ft2

) = 9.29030  10–2 square meter (m2

)

1 square yard (yd2

) = 8.36127  10–1 square meter (m2

)

Density

1 pound per cubic foot (lb/ft3

) = 16.0185 kilograms per cubic

meter (kg/m3

)

Energy

1 kilocalorie (kcal) = 4.1840  103 joules (J)

Force

1 dyne (dynes) = 1  10–5 newton (N)

Length

1 angstrom (a˜) = 10–10 meter (m)

1 inch (in) = 2.54  10–2 meter (m)

1 foot (ft) = 3.048  10–1 meter (m)

1 yard (yd) = 9.144  10–1 meter (m)

Pressure

1 atmosphere (atm) = 0.101325 megapascal (MPa)

1 millimeter of mercury (mmHg) = 133.322 pascals (Pa)

1 pound per square inch (psi) = 6894.76 pascals (Pa)

Surface tension

1 dyne per centimeter (dyne/cm) = 1 millinewton per meter

(mN/m)

Temperature

Celsius (8C) = (1.8  8C) þ 32 Fahrenheit (8F)

Fahrenheit (8F) = (0.556  8F) –17.8 Celsius (8C)

Viscosity (dynamic)

1 centipoise (cP) = 1 millipascal second (mPa s)

1 poise (P) = 0.1 pascal second (Pa s)

Viscosity (kinematic)

1 centistoke (cSt) = 1 square millimeter per second (mm2

/s)

Volume

1 cubic inch (in3

) = 1.63871  10–5 cubic meter (m3

)

1 cubic foot (ft3

) = 2.83168  10–2 cubic meter (m3

)

1 cubic yard (yd3

) = 7.64555  10–1 cubic meter (m3

)

1 pint (UK) = 5.68261  10–4 cubic meter (m3

)

1 pint (US) = 4.73176  10–4 cubic meter (m3

)

1 gallon (UK) = 4.54609  10–3 cubic meter (m3

)

1 gallon (US) = 3.78541  10–3 cubic meter (m3

)