Gas Tank Volume Formula

Calculating Fuel Tank Capacity

If you’re curious about your fuel tank capacity, here is a simple formula to determine the size of your gas tank in gallons.

Simply multiply the length, width, and height (L x W x H) of the gas tank, then divide the total by 231. 231 is the number of cubic inches in one gallon of gasoline.

There are other formulas used for cylindrical tank volumes, however, we use this formula because most Jeep gas tanks are rectangular.

One thing to note when calculating fuel tank capacity is that some tanks can hold more volume than advertised, but you should only fill it to the specified limit when you purchased the item.

For Example, a Cherokee XJ tank measuring 33 inches long, 20 inches wide, and 13 inches high will result in a 37-gallon capacity. However, you may see it advertised as a 20-gallon tank. It may also be because the tank has a pan and internal vent within, occupying space that would otherwise be occupied by gas. When determining your Jeep tank volume, you should slowly fill the tank to avoid overfilling.

Refer to our fuel system diagrams to ensure you're getting the right tank and accessories for your restoration project.