Gas Mileage Calculator — miles per gallon (MPG)

How it works

Gas mileage, or fuel economy, tells you how far a vehicle travels per unit of fuel. It is simply the distance covered divided by the fuel consumed:

MPG = distance ÷ fuel used

In the US this is reported as miles per gallon (MPG), the metric the EPA prints on every new-car fuel-economy label. Fill up, note your odometer, drive until the next fill-up, and divide the miles you covered by the gallons it took to refill.

A higher MPG is better — the car goes farther on the same fuel. The calculator is unit-agnostic, so it also works for kilometres per litre or any consistent distance-and-fuel pair; just read the result in those units.

Worked example

Driving 300 miles on 10 gallons gives 300 ÷ 10 = 30 MPG. An efficient car covering 450 miles on 10 gallons manages 45 MPG, while a thirsty truck doing 200 miles on 20 gallons gets just 10 MPG. A full tank of 12 gallons taking you 400 miles works out to 33.3 MPG.

Frequently asked questions

How do I calculate my gas mileage?

Divide the distance you drove by the amount of fuel you used: MPG = miles ÷ gallons. The most accurate way is to fill the tank, reset the trip odometer, drive normally, then refill and divide the miles driven by the gallons it took to fill back up.

What is a good MPG?

It depends on the vehicle. Many modern cars average 25–35 MPG combined, efficient hybrids reach 50 MPG or more, and large trucks and SUVs may get 15–20 MPG. Higher is better; the EPA combined rating on the window sticker is a useful benchmark.

Why is my real MPG lower than the sticker rating?

EPA ratings come from standardized tests. Real-world mileage is affected by driving style, speed, cold weather, short trips, cargo, tire pressure and air conditioning, so it is often a few MPG below the label. Calculating your own from fill-ups gives your true figure.

Does this work for litres and kilometres?

Yes — the calculator just divides distance by fuel, so kilometres ÷ litres gives km/L. Note that many countries instead quote fuel consumption as litres per 100 km, which is the inverse idea (lower is better); this calculator gives the distance-per-fuel form (higher is better).

How can I improve my gas mileage?

Drive smoothly and avoid hard acceleration and braking, keep to moderate highway speeds, maintain correct tire pressure, remove excess weight, and keep up with servicing. Small habit changes can raise real-world MPG noticeably.

How is MPG related to fuel cost?

Fuel cost per mile is the fuel price divided by MPG, so a higher MPG means a lower cost per mile. Use the [fuel cost](fuel-cost-calculator) calculator to turn your MPG and the fuel price into the cost of a specific trip.