Gas Mileage Calculator

What is a gas mileage calculator? Calculate MPG from distance and fuel used, then compare fuel cost, consumption, and vehicle efficiency.

Interactive inputs
Live result 30.00 MPG

Change an input to update the diagram.

What is a gas mileage calculator?

The Gas Mileage Calculator is the definitive tool for measuring your vehicle's fuel efficiency. Enter distance traveled, fuel consumed, and fuel price to see your MPG, fuel cost per mile, and total trip cost. It serves anyone who fills up a car, truck, or SUV and wants to know exactly how far each gallon takes them.

Current calculator output 30.00 MPG

Gas Mileage Calculator: inputs, formula, and result

Enter the values that describe your high priority scenario. The interactive result changes as the inputs change, helping you compare fuel efficiency, fuel consumption, fuel cost, or operating impact.

Distance360Measured travel
Fuel input12Volume or rate
Efficiency30 MPGCalculated output

Formula

MPG = Distance ÷ Fuel Used; Cost Per Mile = Fuel Price ÷ MPG

Worked example

360 miles on 30 gallons at $3.50/gallon: MPG = 12. Cost per mile = $0.292.

Pro tip: Use the tank-to-tank method: fill up completely, reset your trip odometer, drive normally, fill up again, and divide miles by gallons added.

What changes the result for Gas Mileage?

Use this focused fuel-economy tool to get a direct answer for a common driving-cost question. Traffic, tire pressure, vehicle load, terrain, driving style, weather, fuel price, and the quality of the input data can change the final result.

Estimated result condition 100%
Select factors that match this high priority calculation.

When should you use this calculator?

Use it before a trip, after a fill-up, when comparing vehicles, or when documenting business mileage. Keep the same units and use several measurements when you need an average.

Selected usePlan with Gas Mileage Calculator

FAQs about Gas Mileage

3 questions
Question 1 of 3 is open
How do I calculate gas mileage accurately?

Fill your tank completely, note the odometer, drive normally, fill up again. Divide miles driven by gallons added. Repeat over 3-5 fill-ups and average the results.

What factors most affect gas mileage?

Driving speed (optimal 45-65 mph), acceleration style (gentle is 10-33% better), vehicle weight, tire pressure, AC use, engine maintenance, and weather (cold reduces MPG 10-20%).

Why is my gas mileage getting worse?

Common causes: underinflated tires (-3-5%), dirty air filter (-up to 10%), worn spark plugs (-up to 5%), faulty oxygen sensor (-up to 40%), or more city driving.

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