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Gas Mileage and Fuel Cost

MPG Calculator

Enter miles driven and gallons used to calculate your miles per gallon, fuel cost, cost per mile, L/100 km, and estimated range on a full tank.

mi
Miles Driven slider
11,000 mi
gal
Gallons Used slider
0.150 gal
$
Fuel Price slider
0$8/gal
gal
Tank Size slider
140 gal
Formula: MPG = miles driven / gallons used.

How to Calculate MPG

MPG stands for miles per gallon. The formula is simple: divide the number of miles driven by the gallons of fuel used. EPA explains MPG as the distance a vehicle can travel on one gallon of fuel, and real-world MPG can differ from official ratings.

MPG Formula Examples

Miles Driven
Gallons Used
MPG
300 miles
10 gallons
30 MPG
250 miles
12 gallons
20.83 MPG
420 miles
14 gallons
30 MPG
180 miles
8 gallons
22.5 MPG

How to Measure Your Real-World MPG

  1. Fill your tank and reset the trip odometer.
  2. Drive normally until you need fuel again.
  3. Refill the tank and record the gallons added.
  4. Divide trip miles by gallons added.

Why Your MPG Changes

MPG can drop because of stop-and-go traffic, high speeds, cold weather, low tire pressure, roof racks, heavy cargo, poor maintenance, short trips, or aggressive acceleration. Tracking your own MPG helps you notice changes that official ratings cannot capture.

Frequently Asked Questions

How Do I Calculate My MPG?+

Divide miles driven by gallons used. If you drove 320 miles and used 11.5 gallons, your MPG is 320 / 11.5 = 27.83 MPG.

How Do You Calculate Your Miles Per Gallon?+

Fill the tank, reset the trip odometer, drive normally, refill, then divide trip miles by the gallons needed to refill the tank.

Why Is My MPG Different from the EPA Rating?+

Real-world MPG changes with speed, traffic, tire pressure, weather, cargo, fuel blend, maintenance, and driving habits.

What Is Good MPG?+

Good MPG depends on vehicle type. A compact car may exceed 30 MPG, while trucks and large SUVs often use more fuel.