dopecalc

Gas Mileage Calculator

Calculate your vehicle's fuel efficiency in MPG, cost per mile, total trip cost, and liters per 100 kilometers.

miles
gal
$

About this Calculator

Calculate your vehicle's fuel efficiency in MPG, cost per mile, total trip cost, and liters per 100 kilometers.

Formula & Calculations

Formula

MPG = Distance / Fuel Used; L/100km = (235.215 / MPG)
Where:
  • MPG=Miles per gallon (fuel efficiency)
  • Distance=Total distance traveled in miles
  • Fuel=Fuel consumed in gallons
  • Price=Fuel price per gallon in dollars

Assumptions

  • Distance is measured in miles and fuel in US gallons.
  • L/100km conversion uses standard factor: L/100km = 235.215 / MPG.
  • Cost calculations assume a constant fuel price for the entire trip.

Calculation Examples

Example 1

Inputs:Distance: 300 miles, Fuel: 10 gallons, Price: $3.50/gal
Result:30 MPG, $0.12/mi, $35.00 trip cost, 7.84 L/100km

300 / 10 = 30 MPG. $3.50 / 30 = $0.117/mi. 10 × $3.50 = $35.00. 235.215 / 30 ≈ 7.84 L/100km.

Example 2

Inputs:Distance: 500 miles, Fuel: 20 gallons, Price: $4.00/gal
Result:25 MPG, $0.16/mi, $80.00 trip cost, 9.41 L/100km

500 / 20 = 25 MPG.

Frequently Asked Questions

How can I improve my gas mileage?

Maintain proper tire pressure, reduce excess weight, drive at steady speeds, avoid aggressive acceleration and braking, and keep up with regular engine maintenance.

What is considered good fuel economy?

For most passenger vehicles, 25-30 MPG combined is considered good. Hybrid vehicles can achieve 40-55 MPG, while many modern compact cars reach 30-40 MPG on the highway.