Free Online Fuel Economy (MPG) Calculator
Calculate MPG, L/100km, and Fuel Cost Per Mile
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Knowing your car's actual fuel economy — rather than the manufacturer's sticker estimate — requires tracking real distance traveled against real fuel consumed, then converting that into whichever unit you're used to: miles per gallon in the US, or liters per 100 kilometers almost everywhere else.
Other tools in Automotive Calculators
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
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About Fuel Economy (MPG) Calculator
Knowing your car's actual fuel economy — rather than the manufacturer's sticker estimate — requires tracking real distance traveled against real fuel consumed, then converting that into whichever unit you're used to: miles per gallon in the US, or liters per 100 kilometers almost everywhere else.
This calculator takes the distance you traveled and the fuel you used to compute MPG or L/100km depending on which unit system you select, and also factors in your local fuel price to show the actual cost per mile or per kilometer of driving.
Tracking this over time — after each fill-up, log your trip distance and fuel added — gives a much more realistic picture of your vehicle's real-world efficiency than any published estimate, since it reflects your actual driving conditions, terrain, and habits.
How it works
- Choose your unit system. Select miles/gallons or kilometers/liters.
- Enter distance and fuel used. Input how far you drove and how much fuel that trip used.
- See economy and cost. View your MPG or L/100km, plus cost per unit distance.
Examples
300 miles on 10 gallons
Input
Distance: 300 miles, Fuel: 10 gallons
Output
30.0 MPG