Approximate conversion factors
To
tonnes US tonnes/
Crude oil* (metric) kilolitres barrels gallons year
From         Multiply by    
Tonnes (metric) 1 1.165 7.33 307.86
Kilolitres 0.8581 1 6.2898 264.17
Barrels 0.1364 0.159 1 42
US gallons 0.00325 0.0038 0.0238 1
Barrels/day     49.8
 *Based on worldwide average gravity.
To convert
barrels tonnes kilolitres tonnes
Products to tonnes to barrels to tonnes to kilolitres
        Multiply by
LPG 0.086 11.6 0.542 1.844
Gasoline 0.118 8.5 0.740 1.351
Kerosene 0.128 7.8 0.806 1.24
Gas oil/ diesel 0.133 7.5 0.839 1.192
Residual fuel oil       0.149 6.7 0.939 1.065
To
billion cubic billion cubic million tonnes million tonnes trillion British million barrels
Natural gas and LNG metres NG feet NG oil equivalent LNG thermal units oil equivalent
From   Multiply by
1 billion cubic metres NG 1 35.3 0.90 0.74 35.7 6.60
1 billion cubic feet NG 0.028 1 0.025 0.021 1.01 0.19
1 million tonnes oil equivalent 1.11 39.2 1 0.82 39.7 7.33
1 million tonnes LNG 1.36 48.0 1.22 1 48.6 8.97
1 trillion British thermal units 0.028 0.99 0.025 0.021 1 0.18
1 million barrels oil equivalent 0.15 5.35 0.14 0.11 5.41 1
Units
1 metric tonne = 2204.62 lb. 
= 1.1023 short tons
1 kilolitre = 6.2898 barrels
1 kilolitre = 1 cubic metre
1 kilocalorie (kcal) = 4.187 kJ = 3.968 Btu
1 kilojoule (kJ) = 0.239 kcal = 0.948 Btu
1 British thermal unit (Btu) = 0.252 kcal = 1.055 kJ
1 kilowatt-hour (kWh) = 860 kcal = 3600 kJ = 3412 Btu
Calorific equivalents
One tonne of oil equivalent equals approximately:    
Heat units  10 million kilocalories
42 gigajoules
  40 million Btu    
Solid fuels 1.5 tonnes of hard coal
3 tonnes of lignite
Gaseous fuels See Natural gas and LNG table     
Electricity 12 megawatt-hours    
       
One million tonnes of oil produces about 4400 gigawatt-hours (=4.4 terawatt hours) of electricity in a modern power station.
1 barrel of ethanol = 0.57 barrel of oil
1 barrel of biodisel = 0.88 barrel of oil
1 tonne of ethanol = .57 ton of oil
1 tonne of biodiesel = .88 ton of oil
Other terms
Tonnes: Metric equivalent of tons