Conversion Factors

Conversion formulae for temperature

• ⁰F=(⁰C)(9/5) + 32

• ⁰C=(⁰F - 32)(5/9)

• ⁰R = ⁰F + 459.67

• K = ⁰C + 273.15

Conversion factors for distance

1 inch (in) = 2.540000 centimeter (cm)

1 foot (ft) = 12 inches (in)

1 yard (yd) = 3 feet (ft)

1 mile (mi) = 5280 feet (ft)

Conversion factors for volume

1 gallon (gal) = 231.0 cubic inches (in3) = 4 quarts (qt) = 8 pints (pt) = 128 fluid ounces (fl. oz.)

= 3.7854 liters (l)

1 milliliter (ml) = 1 cubic centimeter (cm3)

Conversion factors for velocity

1 mile per hour (mi/h) = 88 feet per minute (ft/m) = 1.46667 feet per second (ft/s) = 1.60934

kilometer per hour (km/h) = 0.44704 meter per second (m/s) = 0.868976 knot (knot – international)

Conversion factors for mass

1 pound (lbm) = 0.45359 kilogram (kg) = 0.031081 slugs

Conversion factors for force

1 pound-force (lbf) = 4.44822 newton (N)

Conversion factors for area

1 acre = 43560 square feet (ft2) = 4840 square yards (yd2) = 4046.86 square meters (m2)

Conversion factors for pressure (either all gauge or all absolute)

1 pound per square inch (PSI) = 2.03603 inches of mercury (in. Hg) = 27.6807 inches of water (in.

W.C.) = 6.894757 kilo-pascals (kPa)

Conversion factors for pressure (absolute pressure units only)

1 atmosphere (Atm) = 14.7 pounds per square inch absolute (PSIA) = 760 millimeters of mercury

absolute (mmHgA) = 760 torr (torr) = 1.01325 bar (bar)

Conversion factors for energy or work

1 British thermal unit (Btu – “International Table”) = 251.996 calories (cal – “International Table”)

= 1055.06 joules (J) = 1055.06 watt-seconds (W-s) = 0.293071 watt-hour (W-hr) = 1.05506 x 1010

ergs (erg) = 778.169 foot-pound-force (ft-lbf)

Conversion factors for power

1 horsepower (hp – 550 ft-lbf/s) = 745.7 watts (W) = 2544.43 British thermal units per hour

(Btu/hr) = 0.0760181 boiler horsepower (hp – boiler)