International Commonly Used Units Conversion Encyclopedia

Area Conversion

1 square kilometer (km2) = 100 hectares (ha) = 247.1 acres (acre) = 0.386 square miles (mile2)

1 square meter (m2) = 10.764 square feet (ft2)

1 square inch (in2) = 6.452 square centimeters (cm2)

1 hectare (ha) = 10,000 square meters (m2) = 2.471 acres (acre)

1 acre (acre) = 0.4047 hectares (ha) = 4.047× 10-3 square kilometers (km2) = 4047 square meters (m2)

1 acre (acre) = 0.4047 hectares (ha) = 4.047× 10-3 square kilometers (km2) = 4047 square meters (m2)

1 square foot (ft2) = 0.093 square meter (m2)

1 square meter (m2) = 10.764 square feet (ft2)

1 square yard (yd2) = 0.8361 square meters (m2)

1 square mile (mile2) = 2.590 square kilometers (km2)

1 acre is equal to about 667 square meters

1 square kilometer (km2) = 100 hectares (ha) is about equal to 1500 acres

Volume conversion

1 meggill (GI) = 0.118 liters (1) 1 American pint (PT) = 0.473 liters (1)

1 US quart (QT) = 0.946 liters (1) 1 US gallon (gal) = 3.785 liters (1)

1 barrel (bbl) = 0.159 cubic meters (m3) = 42 US gallons (gal) 1 acre·ft = 1234 cubic meters (m3)

1 cubic inch (in3) = 16.3871 cubic centimeter (cm3) 1 English gallon (gal) = 4.546 liters (1)

1 billion cubic feet (BCF) = 28,317,000 cubic meters (m3) 1 trillion cubic feet (TCF) = 28,317 million cubic meters (m3)

1 million cubic feet (MMcf) = 28,317 cubic meters (m3) 1,000 cubic feet (mcf) = 28.317 cubic meters (m3)

1 cubic foot (ft3) = 0.0283 cubic meter (m3) = 28.317 liters (liter)

1 cubic meter (m3) = 1000 liters (liter) = 35.315 cubic feet (ft3) = 6.29 barrels (bbl)

Mass, density conversion

Mass conversion

1 Long Ton = 1.016 T 1 Kilogram = 2.205 lb

1 lb = 0.454 kg [Constant] 1 oz = 28.350 g

1 short ton (sh.ton) = 0.907 tons (t) = 2000 pounds (lb)

1 ton (t) = 1000 kilograms (kg) = 2205 pounds (lb) = 1.102 short ton (sh.ton) = 0.984 long ton (long ton)

Density conversion

1 lb/ft3 ( lb/ft3 ) =16.02 kg / m3 ( kg/m3 )

API degree = 141.5/15.5°C specific gravity -131.5

1 lb/lb/gal = 99.776 kg/m3 (kg/m3)

1 Baumé density (B) = 140/15.5 °C specific gravity -130

1 lb/in3 (lb/in3) = 27679.9 kg/m3 (kg/m3)

1 lb/US gallon (lb/gal) = 119.826 kg/m3 (kg/m3)

1 lb/(petroleum) barrel (lb/bbl) = 2.853 kg/m3 (kg/m3)

1 kg/m3 (kg/m3) = 0.001 g/cm3 (g/cm3) = 0.0624 lb/ft3 (lb/ft3)

Viscosity conversion

Kinematic viscosity conversion

1 S(St) = 10-4 m2/s (m2/s) = 1 cm2/s (cm2/s)

1 ft2/s (ft2/s) = 9.29030×10-2 m2/s (m2/s)

1 cSt = 10-6 m2/s (m2/s) = 1 mm2/s (mm2/s)

Dynamic viscosity conversion

Dynamic viscosity 1 papoise (P) = 0.1 Pa·s (Pa·s) 1 centipoise (cP) = 10-3 Pa·s (Pa·s)

1 lbf·s/ft2 = 47.8803 Pa·s

1 kgf/m2 (kgf·s, m2) = 9.80665 Pa·s (Pa·s)

Force, temperature conversion

Force conversion

1 Newton (N) = 0.225 lbf = 0.102 kilogram-force (kgf)

1 kilogram force (kgf) = 9.81 N(N)

1 lbf = 4.45 Newtons (N) 1 dyne (dyn) = 10-5 Newtons (N)

Temperature conversion

K＝5/9（°F+459.67） K=℃+273.15

n℃=(5/9·n+32) °F n°F=[(n-32)×5/9]℃

1°F = 5/9°C (temperature difference)

Pressure conversion

Pressure: 1 bar = 105 Pa 1 dyne/cm2 (dyn/cm2) = 0.1 Pa

1 Torr = 133.322 Pa 1 millimeter Hg (mmHg) = 133.322 Pa

1 mm water column (mmH2O) = 9.80665 Pa (Pa) 1 engineering atmosphere = 98.0665 kiloPa (kPa)

1 kilopascal (kPa) = 0.145 lbf/in2 (psi) = 0.0102 kgf/cm2 (kgf/cm2) = 0.0098 atm

1 lbf/in2 (psi) = 6.895 kilopascals (kPa) = 0.0703 kgf/cm2 (kg/cm2) = 0.0689 bar = 0.068 atm

1 Atmospheric pressure (atm) = 101.325 kilopascals (kPa) = 14.696 lb/in2 (psi) = 1.0333 bar (bar)

Conversion of heat transfer coefficient, thermal conductivity, specific heat capacity

Heat transfer coefficient conversion

1 kcal/m2·h (kcal/m2·h) = 1.16279 W/m2 (W/m2)

1 kcal/(m2·h·°C)〔1kcal/(m2·h·°C)〕=1.16279 watts/(m2·kelvin)〔w/(m2·K)〕

1 British thermal unit/(ft2·h·°F)〔Btu/(ft2·h·°F)〕 = 5.67826 watts/(m2·kelvin)〔(w/m2·K)〕

1 m2·h·°C/kcal = 0.86000 m2·kelvin/watt (m2·K/W)

Thermal conductivity conversion

1 kcal (m·h·°C) [kcal/(m·h·°C)] = 1.16279 watts/(m·kelvin)〔W/(m·K)〕

1 British thermal unit/(ft·h·°F) [But/(ft·h·°F) = 1.7303 watts/(m·kelvin)] [W/(m·K)]

Specific volume heat conversion

1 kcal/(kg·°C)〔kcal/(kg·°C)〕 = 1 British thermal unit/(lb·°F)〔Btu/(lb·°F)〕 = 4186.8 joules/(kg·kelvin)〔J/(kg·K)〕

Thermal work conversion

1 calorie (cal) = 4.1868 joules (J) 1 kcal = 4186.75 joules (J)

1 kilogram-force meter (kgf·m) = 9.80665 joules (J)

1 British Thermal Unit (Btu) = 1055.06 Joules (J)

1 kWh (kW·h) = 3.6×106 joules (J)

1 foot-pound-force (ft·lbf) = 1.35582 joules (J)

1 meter horsepower hour (hp·h) = 2.64779×106 joules (J)

1 British horsepower hour (UKHp·h) = 2.68452×106 joules

1 joule = 0.10204 kg·m

= 2.778×10-7 kW·h

=3.777×10-7 metric hp hours

=3.723×10-7 British hp hours

= 2.389×10-4 kcal

= 9.48×10-4 British thermal units

Power, speed, permeability conversion

Power conversion

1 British Thermal Unit/hour (Btu/h) = 0.293071 Watts (W)

1 kgf·m/s = 9.80665 watts (W)

1 cal/s = 4.1868 watts (W) 1 meter horsepower (hp) = 735.499 watts (W)

Speed conversion

1 mile/h = 0.44704 meters per second (m/s)

1 ft/s = 0.3048 m/s

Permeability conversion

1 darcy = 1000 millidarcy 1 square centimeter (cm2) = 9.81×107 darcy

Geothermal gradient, oil and gas production, gas-oil ratio conversion

Geothermal gradient conversion

1°F/100 ft = 1.8°C/100 m (°C/m)

1°C/km = 2.9°F/mile = 0.055°F/100ft

Oil and gas production conversion

1 barrel (bbl) = 0.14 tons (t) (crude oil, global average)

1 trillion cubic feet per day (TCFD) = 28.32 billion cubic meters per day (m3/d) = 10.336 trillion cubic meters per year (m3/a)

1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,0

1 million cubic feet/day (MMcfd) = 28,320 cubic meters/day (m3/d) = 10,335,500 cubic meters/year (m3/a)

1,000 cubic feet/day (Mcfd) = 28.32 cubic meters/day (m3/d) = 10,336 cubic meters/year (m3/a)

1 barrel per day (bpd) = 50 tons per year (t/a) (crude oil, global average)

1 tonne (t) = 7.3 barrels (bbl) (crude oil, global average)

Gas-to-oil ratio conversion

1 cubic foot/barrel (cuft/bbl) = 0.2067 cubic meters/ton (m3/t)

Conversion of calorific value and heat equivalent

Calorific value conversion

1 barrel of crude oil = 5.8×106 British Thermal Units (BTU)

1 tonne of coal = 2.406×107 British Thermal Units (Btu)

1 cubic meter of moisture = 3.909×104 British thermal units (Btu)

1 kWh hydropower = 1.0235×104 British thermal (Btu)

1 cubic meter of dry gas = 3.577×104 British thermal units (Btu) (the above is the average calorific value of the United States in 1990)

(Source: National Bureau of Standards)

Heat equivalent conversion

1 barrel of crude oil = 5,800 cubic feet of natural gas (calculated at average calorific value)

1 cubic meter of natural gas = 1.3300 kg of standard coal

1 kg of crude oil = 1.4286 kg of standard coal