Gas Mileage Calculator

Calculate your vehicle's gas mileage (MPG) from distance driven and fuel consumed. Choose between distance or odometer method. See cost per mile and metric equivalents.

Gas Mileage

25.0 MPG

km/L

10.6

L/100km

9.4

Cost/Mile

$0.13

๐Ÿ’ก MPG = Distance รท Fuel = 300 mi รท 12.0 gal = 25.0 MPG

ByPRIYA SHARMAโ€ขUpdated April 4, 2026
|
Reviewed byARJUN MEHTA
|
Fact checked byNEHA KAPOOR

๐Ÿ’ก How to Use the Gas Mileage Calculator

How to Calculate Gas Mileage

Gas mileage, measured in miles per gallon (MPG), tells you how far your vehicle travels on one gallon of fuel. Higher MPG means better fuel efficiency and lower fuel costs.

MPG = Miles Driven รท Gallons Used

Two Methods to Calculate

Distance Method: If you know the total trip distance and how much fuel you used, simply divide: 300 miles รท 12 gallons = 25 MPG.

Odometer Method: Fill your tank, note the odometer reading. At next fill-up, note the new reading and gallons added. Subtract to get miles driven, then divide by gallons.

What Affects Your MPG?

FactorImpact on MPG
City vs HighwayHighway is 20โ€“30% better due to less braking
Speed over 60 mphEach 5 mph over 60 = ~7% worse MPG
Aggressive drivingRapid acceleration/braking = 15โ€“30% worse
Tire pressure (low)Every 1 PSI low = 0.2% worse MPG
AC usage3โ€“4% worse in the city
Cold weather15โ€“24% worse (under 20ยฐF)
Roof rack/cargo2โ€“8% worse due to wind drag

Tips to Improve Your MPG

  • Maintain proper tire pressure โ€” check monthly
  • Drive smoothly โ€” gradual acceleration and coasting to stops
  • Use cruise control on highways
  • Remove excess weight โ€” every 100 lbs costs ~1% MPG
  • Keep up with maintenance โ€” clean air filter, fresh oil, new spark plugs

Gas Mileage Calculator FAQ