MPG Calculator
Enter the miles driven, gallons used, and price per gallon from your last fill-up to calculate your vehicle's actual fuel efficiency (MPG), cost per mile driven, and the total fuel expense. Track your real-world efficiency over time.
Advertisement
Calculator
See your MPG Calculator results
Enter your email to unlock results — free forever.
No spam, ever. Unsubscribe at any time.
Advertisement
Formula
MPG = Miles Driven ÷ Gallons Used
Miles per gallon is the ratio of distance traveled to fuel consumed. Cost per mile divides the price per gallon by MPG — the more efficient your vehicle, the lower the cost per mile. Total fuel cost is simply gallons used multiplied by price per gallon, confirming the fill-up cost.
How to use the MPG Calculator
- 1
Enter your miles driven
- 2
Enter your gallons used
- 3
Enter your price per gallon ($)
- 4
Read your results instantly
Results update in real time as you type.
Advertisement
How to Measure Real-World MPG
For an accurate reading, fill your tank completely, reset your trip odometer, drive normally, then fill up again completely. Record the miles on the odometer and the gallons pumped. Enter those numbers here. One fill-up gives a snapshot; averaging three or more gives a reliable baseline. Your real-world MPG typically falls 10-20% below the EPA estimate due to driving habits, traffic, and load.
What Affects Fuel Efficiency?
Speed is the biggest factor: every 5 mph over 60 reduces efficiency by roughly 7%. Tire pressure, air filter condition, and extra cargo weight also matter. Air conditioning can cut MPG by 5-25% in city driving. Cold weather reduces MPG because engines take longer to warm up and winter-blend fuels have slightly less energy. Tracking MPG monthly reveals trends tied to seasons and maintenance schedules.
Tips & Insights
Track Fill-Up History
Keep a fuel log (or use an app like Fuelly) to spot declining MPG, which often signals a maintenance issue like low tire pressure or a dirty air filter.
Hypermiling Techniques
Gentle acceleration, coasting to stops, and maintaining steady highway speeds are the easiest ways to improve real-world MPG without modifying your car.
Compare to EPA Rating
If your MPG is more than 15% below the EPA estimate, check tire pressure, replace the air filter, and consider a tune-up.
Worked Examples
Typical Fill-Up
29.17 MPG, $0.12/mile, $42.00 fill-up.
Efficient Hybrid
50 MPG, $0.07/mile, $35.00 fill-up.
Advertisement
Frequently Asked Questions
What is a good MPG?
For gas-powered cars, 30+ MPG is good, 40+ is excellent. SUVs and trucks averaging 20-25 MPG are typical. Hybrids often exceed 45 MPG.
How do I improve my MPG?
Maintain proper tire pressure, avoid aggressive acceleration and braking, reduce highway speeds, keep up with oil changes, and minimize idling.
Why is my real MPG lower than the EPA estimate?
EPA tests are conducted under controlled conditions. Real driving involves traffic, climate, payload, and driving style — all of which reduce efficiency.
What is cost per mile useful for?
Cost per mile lets you compare fuel expenses across vehicles with different efficiencies and fuel prices, and estimate the fuel portion of any trip cost.
Can I enter liters and kilometers?
Not directly. Convert km to miles (multiply by 0.621) and liters to gallons (multiply by 0.264) before entering, or use an L/100km calculator.
Advertisement