Gas Mileage Calculator

How to Calculate Gas Mileage (MPG)

Miles per gallon (MPG) tells you how efficiently your vehicle uses fuel. Higher MPG means lower fuel costs.

The formula

MPG = Miles Driven ÷ Gallons Used

Step-by-step (the fill-up method)

1. Fill your tank completely and reset your trip odometer to zero.
2. Drive normally until it is time to refuel.
3. Fill the tank again and note how many gallons it takes to fill.
4. Check your trip odometer for total miles driven.
5. Enter miles and gallons into the calculator.
6. Optionally enter the price per gallon to see your trip fuel cost.

Worked example

300 miles driven, 10 gallons to refill. MPG = 300 ÷ 10 = 30 MPG. At .50/gallon, trip cost = 10 × .50 = .

Tips to improve MPG

Keep tires properly inflated, remove excess weight, avoid aggressive acceleration and braking, maintain steady highway speeds, and keep up with regular maintenance. Air conditioning use at low speeds reduces MPG; at highway speeds, windows open may be worse.