Miles Per Tank Calculator
Knowing how far you can drive on a single tank makes trip planning easier and helps you avoid running out of fuel on a long stretch of road. This miles per tank calculator estimates your driving range from two numbers: the usable capacity of your fuel tank in gallons and your vehicle's fuel economy in miles per gallon. It multiplies the two to give the total miles you can expect from a full tank, which is handy for spacing out fuel stops, comparing the practical range of different vehicles, or deciding whether you can reach the next town without topping up. The figure it returns is a theoretical maximum at the mpg you enter, so in practice you should plan to refuel with a comfortable reserve rather than pushing to the last drop. Real-world range falls short of the calculation when conditions are tough: city traffic, high speeds, cold weather, hills and heavy loads all cut mpg. Because tank size and real economy vary by vehicle and by trip, both inputs are fully editable. The calculation is a single multiplication, shown in the formula below, with a worked example that reconciles exactly to the calculator defaults so you can check it yourself.
Range on a full tank is capacity times economy: range = tank gallons x mpg. A 14 gallon tank in a car returning 32 mpg gives a driving range of 448 miles before refueling.
Miles per tank formula
Range = T x E
T = usable tank capacity in gallons
E = fuel economy in miles per gallon
The full tank holds T gallons, and each gallon carries the car E miles, so the product is the total distance the tank can cover at that economy.
Worked example
Your vehicle has a 14 gallon tank and returns 32 miles per gallon.
- Range = tank x mpg
- Range = 14 x 32
- Range = 448 miles
A full tank gives about 448 miles of range. These are the calculator's default inputs, so the result above matches the widget exactly.
Miles per tank calculator: frequently asked questions
How do I work out my miles per tank?
Multiply your fuel tank's usable capacity in gallons by your vehicle's miles per gallon. A 14 gallon tank in a car that returns 32 mpg gives 448 miles of range on a full tank. This is the theoretical maximum at the mpg you enter, so plan to refuel well before reaching it.
Where do I find my tank capacity?
Fuel tank capacity is listed in the owner's manual and often on the manufacturer's specification sheet, given in gallons. Keep in mind that the usable capacity is usually a little less than the rated figure, because most cars will not let you draw the tank completely dry. For a safety margin, treat the last gallon or two as a reserve.
Why is my real range shorter than the calculation?
Real-world range depends on driving conditions. City traffic, hard acceleration, high speeds, cold weather, air conditioning, hills and a heavy load all lower mpg below the rated figure, which shortens range. The calculator uses whatever mpg you enter, so for a realistic result use your own measured economy rather than the optimistic sticker number.
Should I run the tank down to empty?
It is best not to. Running consistently very low can leave you stranded and, in some vehicles, the fuel pump relies on fuel for cooling, so chronic near-empty driving may shorten its life. Treat the calculated range as a maximum and refuel with a comfortable reserve, especially on long or remote trips.
What is the miles per tank formula?
Range equals tank capacity in gallons multiplied by miles per gallon. With a 14 gallon tank and 32 mpg, that is 14 times 32, which equals 448 miles on a full tank.
Official sources
- Travel and transportation safety guidance: US Centers for Disease Control and Prevention (CDC). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.