Gas Mileage Calculator
Calculate your car's MPG, litres per 100 km, and total fuel cost per trip.
Gas Mileage Calculator
Calculate your car's MPG, litres per 100 km, and total fuel cost per trip.
Engineering Calculation
ℹ️ Used for basic engineering ratio and product calculations
Disclaimer
Results provided by this calculator are for informational and educational purposes only. They are based on the values you enter and standard formulas, and should not be considered financial, medical, legal, or professional advice. Always consult a qualified professional before making important decisions based on these results. Roughtools makes no warranties regarding the accuracy or completeness of these calculations for your specific situation.
Frequently Asked Questions
Pro Tips
Always verify critical calculations with a second method or source — for important decisions, this tool provides a starting point, not a final answer.
Input accuracy determines output accuracy. Use precise values rather than rough estimates for the most useful results.
Run the calculation multiple times with slightly different inputs to understand the sensitivity of the result to your assumptions.
For professional, financial, medical, or legal decisions, always confirm results with a qualified professional before acting.
When to Use This Calculator
Use the Gas Mileage Calculator for fast, accurate calculations without installing any software.
Understand the formula and see how changing inputs affects the result for educational purposes.
Get a quick estimate before performing more detailed analysis or consulting a professional.
Accessible from any device — no app to install, no account required, works offline after loading.
Run multiple scenarios quickly by changing one input at a time to understand sensitivities.
About the Gas Mileage Calculator
This gas mileage calculator computes your vehicle's actual fuel economy in MPG (US), MPG (Imperial), and L/100km from real fill-up data — odometer readings and gallons pumped — rather than EPA estimates. Enter two consecutive odometer readings and the gallons filled to see your real-world MPG, total fuel cost, and cost per mile. Track multiple fill-ups to identify trends in fuel efficiency over time. Built for drivers monitoring vehicle health, comparing vehicles, or tracking business mileage.
How to Use the Gas Mileage Calculator
- 1
Record your odometer reading when you fill up completely (tank full).
- 2
Drive until your next fill-up and record the new odometer reading.
- 3
Enter both odometer readings and the number of gallons pumped at the second fill-up.
- 4
See your actual MPG, L/100km, miles driven, and cost per mile.
- 5
Add multiple fill-up records to track fuel economy trends over weeks or months.
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