Pounds are a measurement of weight, while gallons are a measurement of volume. Therefore, even though both units are part of the imperial system, it is not possible to directly convert pounds to gallons. It is necessary to know the density of the material being measured to convert pounds to gallons. The density of peanut oil is about 0.91 grams per milliliter. 35 pounds of peanut oil equals 4.6 gallons.

There are 450 grams in 1 pound. To convert pounds to grams, multiply the number of pounds by 450. 35 pounds x 450 = 15875.7 grams. The equation for density is mass divided by volume. Mass is another word for weight. To convert mass to volume, divide the mass by the density of the material. 15875.7 grams / 0.91 grams per milliliter = 17445.82 milliliters. There are 17445.82 milliliters of peanut oil in 35 pounds of peanut oil. There are roughly 4000 milliliters in 1 gallon.

To covert the result from milliliters to gallons, divide the number of milliliters by 4000. 17445.82 milliliters / 4000 = 4.6 pounds. The result is that 35 pounds of peanut oil equals about 4.6 gallons of peanut oil. A rise in temperature will decrease the density of the oil and lead to an increase in volume. For each 15 degree Celsius temperature increase, oils can be expected to increase in volume by 1 percent of their total volume.