How to Calculate the Exact Gas Cost of Your Next Road Trip

Whether you are driving three hours to visit family or embarking on a cross-country adventure, the biggest expense of any road trip (other than hotels) is fuel.

With gas prices fluctuating constantly, estimating your travel costs can feel like a guessing game. However, with three simple pieces of information, you can calculate the exact cost of your trip down to the penny.

What You Need to Know

To calculate your fuel cost, you need to find:

1. Total Distance: The total miles you will be driving. Don't forget to double it if it's a round trip!
2. Vehicle MPG: Your car's average "Miles Per Gallon." You can usually find this on your dashboard display or by searching your car's make and model online. Highway MPG is usually slightly higher than city MPG.
3. Average Gas Price: Look up the current average price of gas in the states you will be driving through.

The Fuel Cost Formula

The math is quite simple once you have those three numbers.

First, calculate how many gallons of gas you'll use: Total Distance ÷ Vehicle MPG = Gallons Used

Then, calculate the cost of those gallons: Gallons Used × Gas Price = Total Fuel Cost

If you are driving 600 miles (round trip) in a car that gets 25 MPG, and gas is $3.50 a gallon:

• 600 ÷ 25 = 24 gallons of gas.
• 24 × $3.50 = $84.00 total cost.

Skip the Manual Math

Want to figure out your travel budget instantly? Use our free Gas Cost Calculator. Just plug in your distance, MPG, and current gas prices, and we'll tell you exactly how many gallons you'll burn and how much it will cost.