## Best answer

The formula to calculate gas mileage:Miles driven gallons used to refill the tank. Take the miles traveled (from the trip computer), divide that by the number of gallons used to refill the tank. For example, the trip shows 200 miles since you last filled up, and it took 15 gallons to refill the tank.

## People also ask

### How do you calculate gas cost per mile?

If you supply price per gallon or price per liter, the gas calculator will also output gas cost per mile and miles per 1 USD, and if using the metric system the fuel cost will be in currency per kilometer (e.g. $ per km) and km per $. The formula to calculate mpg is: Gas mileagempg = (Current reading – Previous reading) / (Gas added to tank)

### How does the fuel economy calculator work?

It takes account of gas price or fuel cost in the currency you choose, the car efficiency expressed either in gallons per mile or in liters per mile and by one of the two options available (either the distance you are willing to travel or the budget you can afford ).

### How do I know how many miles per gallon I’m getting?

Probably a display on your dash of the mpg (miles per gallon) you are getting. Ie. How many miles you can drive using one gallon of fuel. This number will vary from about 6mpg to 60mpg depending on the vehicle you drive. The number that is displayed on your dash may not be exactly correct. Just like a trip computer, these can also be reset.

### What is the MPG formula?

MPG formula. The formula to calculate mpg is: Gas mileage mpg = (Current reading – Previous reading) / (Gas added to tank) Calculating the cost per mile (or cost per kilometer), which is something our mpg calculator also does, is just a matter of a slight modification of the above formula: