The conversion of metric tons to barrels must use a density factor because a metric ton is a measure of mass or weight and a barrel is a unit of volume. In addition, a metric ton is a metric unit and a barrel is an English unit, so conversion factors must be used to convert the metric ton to an English pound. Crude oil is typically measured in barrels and makes a convenient example for this conversion.

Determine the density of California crude oil (see Resources). The specific gravity of California crude oil is 915 kilograms per cubic meter. This must be converted to English units of pounds per gallon. One kilogram per cubic meter is equal to 0.0083 lb. per gallon, so 915 kilograms per cubic meter equals 7.59 lb. per gallon (915 x 0.0083).

Convert metric tons to English pounds and gallons to barrels. A metric ton is equal to 2,205 lb. There are 42 gallons in a standard barrel.

Convert metric tons to barrels using the properties of California crude oil as an example. Assume there are 25 metric tons of crude oil. If there are 2,205 lb. per metric ton, 25 metric tons is equivalent to 55,125 lb. (25 x 2,205 = 55,125). The density of California crude oil is 7.59 pounds per gallon.

Convert the mass of crude oil to volume by dividing by the density. In this example, 55,125 lb. of oil equals 7,263 gallons of oil (55,125/7.59). Finally, convert gallons of oil to barrels by dividing the volume by the conversion of 42 gallons per barrel. This gives an answer of approximately 172.9 barrels (7,263 / 42). Therefore, 25 metric tons of crude oil is approximately equal to 173 barrels.