How to Calculate Your MPG
Odometer Method
MPG can be calculated in four easy steps:
Step 1.
Fill the vehicle's gas tank completely and write down the vehicle's odometer reading (mileage).
Example: The last time the tank was filled, the odometer reading was 32,645.1 miles.
Step 2.
When it's time to refuel, fill the tank completely and write down the number of gallons it took to fill the tank and the vehicle's new odometer reading. Once two odometer readings are taken, MPG can be calculated.
Example: The next time the tank was filled, the odometer reading was 33,001.3. It took 13.5 gallons to fill the tank.
Step 3.
Calculate the distance driven by subtracting the previous odometer reading from the new one.
Example: The distance driven would be 33,001.3 minus 32,645.1, or 356.2 miles.
Step 4.
Divide the number of miles driven by the number of gallons it took to fill the tank. The result is the vehicle's MPG for that driving period.
Example: 356.2 miles divided by 13.5 gallons equals 26.4 miles per gallon.
The MPG for that driving period would be 26.4.
Trip Odometer Method
If you use your vehicle's trip odometer, MPG can be calculated as follows:
Step 1.
Fill the vehicle's gas tank completely and re-set the trip odometer.
Note: Sometimes it's easy to get the main odometer and trip odometer readings confused, especially if the vehicle is new.
Step 2.
When it's time to re-fuel
- Fill the tank completely
- Write down the number of gallons it took to fill the tank
- Write down the mileage on the trip odometer
- Re-set the trip odometer
Example: It took 9.5 gallons to completely fill the tank, and the trip odometer reads 335 miles.
Step 3.
Divide the number of miles driven by the number of gallons it took to fill the tank. The result is the vehicle's MPG for that driving period.
Example: 335 miles divided by 9.5 gallons equals 35.5 miles per gallon.