Fuel Mileage Calculator

Fuel mileage, or gas mileage, refers to the distance a vehicle can travel per unit of fuel consumed. Typically it is expressed in miles per gallon (mpg) in countries using the imperial system or kilometers per liter (km/L) in countries using the metric system. Fuel mileage is an important measurement for knowing how efficiently your vehicle uses fuel and helps you estimate fuel costs for a trip.

How to calculate fuel mileage

Gas mileage can be calculated using odometer readings and trip distance. The basic formula involves dividing the total distance by the amount of fuel consumed during that trip.

Mileage Value Miles/ Gallon Kilometers/ Liter Liters/100 km Rating
Excellent 50 21.25 4.7 🟢 Excellent
Good 30 12.75 7.8 🟡 Good
Average 20 8.5 11.8 🟡 Average
Poor 10 4.25 23.5 🔴 Poor

Table 1 shows the fuel efficiency rating system, comparing mileage values in miles per gallon, kilometers per liter, and liters per 100 km.

1. Odometer Reading

This method for calculating fuel mileage for a single trip is by using the odometer readings (final odometer reading – initial odometer reading) and the total amount of fuel (in gallons) consumed during that trip.

Fuel Mileage = Distance Travelled/Fuel Consumed

The method of calculation is perfect for calculating gas mileage for a trip. It provides accurate measurement of mileage for a single journey, which can be useful for short-term planning.

Example 1:
Initial Reading : 10,000 miles
Final Reading : 10,300 miles
Fuel Consumed: 10 gallons
10,300 − 10,000 = 300miles
Fuel Mileage = 300/10 = 30 mpg

Example 2:
Initial Reading : 12,500 miles
Final Reading : 12,950 miles
Fuel Consumed : 15 gallons
12,950−12,500 = 450 miles
Fuel Mileage = 450/15 = 30 mpg

2. Using Trip Distance

When you know the total distance traveled and amount of gas consumed, you can easily calculate the gas mileage using the simple mathematical formula. This method is very helpful when you complete data of the trip, such as total distance covered and total gas consumed.

Gas Mileage = Trip Distance/Fuel Used

Where; Trip Distance: The total distance travelled during the trip and Fuel consumed; The total amount of fuel consumed during the trip.

Example 1:
Trip Distance : 250 miles
Total Gas Used : 10 gallons
250/10 = 25 miles per gallon.

Example 2:
Trip Distance : 400 kilometres
Total Gas Used : 20 liters
400/20 = 20 kilometres per liter

Unit Miles/Gallon Kilometers/Liter Liters/100 km Gallons/100 Miles
Miles per Gallon 1 0.425 235.2 / mpg 100 / mpg
Kilometers/Liter 2.352 1 100 / km/L 42.51 / km/L
Liters per 100 km 235.2 / L/100km 100 / L/100km 1 L/100km * 2.352
Gallons/100 Miles 100 / G/100mi G/100mi * 0.425 235.2 / G/100mi 1

Table 2: Gas mileage values across different measurement systems, such as those used in the United States (miles per gallon) and Europe (liters per kilometers).

How to use this calculator

Step 1: The first in calculating fuel mileage is to choose how you want to enter the data. This calculator provides two options: the vehicle’s odometer readings and trip distance.

Step 2: Depending on the selected input method in step 1, you will need to enter specific data: If you chose Odometer Readings, enter the start and end odometer readings. If you chose Trip Distance Enter the total distance traveled. Next, enter the total amount of fuel consumed.

Step 3: Fuel efficiency can be measured in different units. This calculator allows you to choose several units that best suit your preference. Select options from the dropdown menu.

Step 4: Once you have entered all the data, click the calculate button to process the entered data. The result will be displayed in the output field with the selected measurement unit.

1. What is good fuel mileage?

40+ MPG (excellent), 30–40 MPG (good), 20–30 MPG (average), and below 20 MPG (poor).

To calculate gas mileage use the formula: Total distance ÷ Fuel used.

Yes, mileage can be calculated in either kilometres or miles depending on the country or region.