Unit Conversion Factors
The conversion factors shown below are approximate and were taken from a variety of sources. When dealing with liquid or gaseous hydrocarbons, the actual volume, weight, mass, or heat content may depend upon a range of factors such as the specific gravity of the fluid, the amount (if any) of water entrained in the mixture, the temperature and pressure at which the measurements are taken, and other factors. Consequently, in many cases there is no single factor that can be used for conversion. The factors below may be used as rules of thumb and will work for general comparison purposes or calculations.
Thermal conversion factors measure the equivalent heating content of various fuels in British Thermal Units (Btus). In the U.S., common practice is to use the gross or upper end of the range of heat content values for a specific product. In Europe, net or lower end heat content rates are typically used. The difference is the amount of energy that is consumed to vaporize the water created during the combustion process. This difference is typically 2 to 10%, depending on the specific fuel and its hydrogen content. Some fuels, such as unseasoned wood, can be more than 40% different in their gross and net heat content rates. [Source: U.S. Department of Energy, Energy Information Administration] Conversion tables included:
 Volume
 Mass/Weight
 Length
 Area
 Energy
 Approximate Heat Content of Petroleum Products
 Million Btu (MMBtu) per Barrel
Volume
Unit  Multiplied By  Approximate Conversion Factor  Equals  Unit 

Barrels of oil (bbl)  X 
42 
= 
US gallons (gal) 
Barrels of oil (bbl)  X 
34.97 
= 
Imperial gallons (UK gal) 
Barrels of oil (bbl)  X 
0.136 
= 
Tonnes of oil equivalent (toe) 
Barrels of oil (bbl)  X 
0.1589873 
= 
Cubic meters (m3) 
Barrels of oil equivalent (boe)  X 
5,658.53 
= 
Cubic feet (f3) of natural gas 
Tonnes of oil equivalent (toe)  X 
7.33 [1] 
= 
Barrels of oil equivalent (boe) 
Cubic yards (y3)  X 
0.764555 
= 
Cubic meters (m3) 
Cubic feet (f3)  X

0.02831685
 =
 Cubic meters (m3) 
Cubic feet (f3) of natural gas  X 
0.0001767 
= 
Barrels of oil equivalent (boe) 
US gallons (gal)  X 
0.0238095 
= 
Barrels (bbl) 
US gallons (gal)  X 
3.785412 
= 
Liters (l) 
US gallons (gal)  X 
0.8326394 
= 
Imperial gallons (UK gal) 
Imperial gallons (UK gal)  X 
1.201 
= 
US gallons (gal) 
Imperial gallons (UK gal)  X 
4.545 
= 
Liters (l) 
[1] This conversion can range from 6.5 to 7.9 depending on the type of crude oil. This factor is intended to provide an approximation that can be used when the exact factor is unknown. 
Mass/Weight
Unit  Multiplied By  Approximate Conversion Factor  Equals  Unit 

Short tons  X 
2,000 
= 
Pounds (lb) 
Short tons  X
 0.9071847 
= 
Metric tonnes (t) 
Long tons  X 
1.016047 
= 
Metric tonnes (t) 
Long tons  X 
2,240 
= 
Pounds (lb) 
Metric tonnes (t)  X 
1,000 
= 
Kilograms (kg) 
Metric tonnes (t)  X 
0.9842 
= 
Long tons 
Metric tonnes (t)  X 
1.102 
= 
Short tons 
Pounds (lb)  X 
0.45359237
 =
 Kilograms (kg) 
Kilograms (kg)  X 
2.2046 
= 
Pounds (lb) 
Length
Unit  Multiplied By  Approximate Conversion Factor  Equals  Unit 

Miles (mi)  X 
1.609344 
= 
Kilometer (km) 
Yards (yd)  X 
0.9144 
= 
Meters (m) 
Feet (ft)  X 
0.3048 
= 
Meters (m) 
Inches (in)  X 
2.54 
= 
centimeters (cm) 
Kilometer (km)  X 
0.62137 
= 
miles (mi) 
Area
Unit  Multiplied By  Approximate Conversion Factor  Equals  Unit 

Acres  X 
0.40469 
= 
Hectares (ha) 
Square miles (mi2)  X 
2.589988 
= 
Square kilometers (km2) 
Square yards (yd2)  X 
0.8361274 
= 
Square meters (m2) 
Square feet (ft2)  X 
0.09290304 
= 
Square meters (m2) 
Square inches (in2)  X 
6.4516 
= 
Square centimeters (cm2) 
Energy
Unit  Multiplied By  Approximate Conversion Factor  Equals  Unit 

British Thermal Units (Btus)  X 
1,055.05585262 
= 
Joules (J) 
Calories (cal)  X 
4.1868 
= 
Joules (J) 
Kilowatt hours (kWh)  X 
3.6 
= 
Megajoules (MJ) 
Therms  X 
100,000 
= 
British thermal units (Btus) 
Tonnes of oil equivalent  X 
10,000,000 
= 
Kilocalories (kcal) 
Tonnes of oil equivalent  X 
396.83 
= 
Therms 
Tonnes of oil equivalent  X 
41.868 
= 
Gigajoules (GJ) 
Tonnes of oil equivalent  X 
11,630
 =
 Kilowatt hours (kWh) 
Cubic feet (f3) of natural gas  X 
1,025 
= 
British Thermal Units (Btus) 
Approximate Heat Content of Petroleum Products Million Btu (MMBtu) per Barrel
Energy Source  MMBtu/bbl  Energy Source  MMBtu/bbl 

Crude Oil  5.800  Natural Gasoline  4.620 
Natural Gas Plant Liquids  3.735  Pentanes Plus  4.620 
Asphalt  6.636  Petrochemical Feedstocks:  
Aviation Gasoline  5.048  Naphtha < 401° F  5.248 
Butane  4.326  Other oils >= 401° F  5.825 
ButanePropane (60/40) Mixture  4.130  Still Gas  6.000 
Distillate Fuel Oil  5.825  Petroleum Coke  6.024 
Ethane  3.082  Plant Condensate  5.418 
EthanePropane (70/30) Mixture  3.308  Propane  3.836 
Isobutane  3.974  Residual Fuel Oil  6.287 
Jet Fuel, Kerosenetype  5.670  Road Oil  6.636 
Jet Fuel, Naphthatype  5.355  Special Naphthas  5.248 
Kerosene  5.670  Still Gas  6.000 
Lubricants  6.065  Unfinshed Oils  5.825 
Motor Gasoline  Conventional 5  5.253  Unfractionated Stream  5.418 
Motor Gasoline  Oxygenated or Reformulated  5.150  Waxes  5.537 
Motor Gasoline  Fuel Ethanol  3.539  Miscellaneous  5.796 
Source: U.S. Department of Energy, Energy Information Administration (2001) 