Barrels and tons of crude oil are common to both the number of units. OPEC crude oil and Britain and other Western countries, the number of units is usually expressed in barrels, China and Russia and other countries are commonly tons of crude oil as the number of units. Conversion relationship between t and barrel are: 1 ton is equal to about 7 barrels, if oil lighter (diluted) is one ton equals about 7.2 barrels or 7.3 barrels. Gas stations in the U.S. and Europe and other countries, usually done gallon units, with a liter of petrol stations is denominated. 1 barrel = 158.98 liters = 42 gallons. American 1 gallon = 3.785 liters, imperial 1 gallon = 4.546 liters. If you want converted into volume weight, and density of the crude oil related. Assuming a real estate crude oil density of 0.99 kg / l, then the weight of a barrel of crude oil is 158.98 × 0.99 = 157.3902 kg.