Find out what your car really burns.
Enter the miles you drove and the gallons you pumped and see your true fuel economy: MPG, the metric L/100km, your cost per mile, and what a year of driving actually costs at the pump.
Your fill-up
The US average is about 13,500 miles a year. Adjust it to match your driving.
What your numbers mean
How you stack up against typical vehicles
Your MPG vs common vehicle classes
How MPG drives your cost per mile
Economy scorecard
Fuel cost at different MPG
What 1,000 miles and a full year of driving cost at your fuel price, from a thirsty truck to a hybrid. Your result is highlighted.
| MPG | L/100km | Cost per mile | Per 1,000 miles | Per year |
|---|
Fuel economy, explained
How to Calculate Your MPG
Divide the miles driven by the gallons of fuel used. For the most accurate reading, fill your tank completely, reset your trip odometer, drive normally, then fill up again and record the gallons. Your MPG is the trip miles divided by the gallons pumped.
MPG vs Liters per 100km
The US uses miles per gallon (MPG), while most other countries use liters per 100 kilometers (L/100km). To convert MPG to L/100km, divide 235.215 by the MPG value. Higher MPG is better; lower L/100km is better.
Factors That Affect Gas Mileage
Key factors include driving style (aggressive driving reduces MPG by 15-30%), vehicle maintenance, tire pressure, weather (cold weather reduces MPG), terrain (hills reduce MPG), cargo weight, and use of air conditioning.
Tracking Your Fuel Economy
Track your MPG over multiple fill-ups to get an accurate average. A sudden drop in fuel economy can indicate a maintenance issue like underinflated tires, a dirty air filter, or an engine problem that needs attention.
Common questions
What is considered good gas mileage?
For passenger cars, 30+ MPG is good and 40+ MPG is excellent. For SUVs, 25+ MPG is good. For trucks, 20+ MPG is good. Hybrid vehicles typically achieve 40 to 60 MPG, and plug-in hybrids can exceed 100 MPGe.
Why is my actual MPG lower than the EPA rating?
EPA ratings are based on standardized tests. Real-world MPG is often 10% to 20% lower due to aggressive driving, city traffic, short trips, cold weather, and use of accessories like A/C. Highway driving usually comes closest to the rating.
How do I convert MPG to liters per 100km?
Divide 235.215 by your MPG value. For example, 30 MPG equals 235.215 / 30 = 7.84 L/100km. This calculator performs the conversion automatically.
Does ethanol fuel affect my MPG?
Yes. E10 (10% ethanol) reduces MPG by about 3% compared to pure gasoline. E15 (15% ethanol) reduces it by about 4-5%. E85 (85% ethanol) reduces MPG by 20-30%. Ethanol contains less energy per gallon than gasoline.
Estimates for planning only. Real fuel economy varies with driving style, terrain, weather, tire pressure, cargo weight and vehicle condition. Track several fill-ups for a reliable average.