How To Estimate The Cost Of Gas For A Road Trip

How To Estimate The Cost Of Gas For A Road Trip
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Easy calculations for budgeting the cost of gas during a road trip.

There are a lot of important factors that go into prepping for a road trip. Estimating the cost of gas and knowing how to make the proper calculations is essential for sticking to your budget and feeling financially secure during your adventure. Working out the expense of gas costs by calculating your mileage, cost of fuel prices, and making the proper reductions when necessary.

Many travelers believe road trips are a way to cut costs while planning trips, cutting out costs of flights and airline services. While this may be the case in some circumstances, many forget to average the cost of gas during their time on the road. Being properly educated and aware of the amount of money needed for transportation costs can save you and lot of stress, time, and money in the long run.

Knowing prior to your trip how much gas will cost, will allow you to make the correct financial decisions in other aspects of your trip. Use this guide to properly estimate the current price of gas by using the miles your car gets per gallon, and the miles you intend to drive on your trip.

Gas Cost Calculator

Gas Cost Calculator

Enter the following information to calculate the cost of gas per mile:


Here's everything you'll need to have an accurate estimate of the cost of gas for your road trip!

Find out the current price of gas

The first step to estimating the amount of money you will spend on gas during your road is to determine the current price of gas in your area. While you can never be totally accurate every time, knowing the average price is enough to go by. This can be done by looking up the Average National Gas Price on AAA or another reliable source.

Estimate the mileage per gallon of your vehicle

The next step you will need to take in calculating gas costs is to estimate your vehicle's gas mileage (MPG), to the number of miles you can travel per gallon of gas. Keep in mind your actual MPG can vary due to certain driving styles, such as a need for speed or consistent use of cruise control. Additionally, make adjustments for city and highway miles, as this will require a lot more stopping and starting, which uses more gas, causing a lower MPG average.

To learn your estimated miles per gallon, calculate it the next time you fill up your car. Write down the odometer reading of your car and drive normally until your gas light comes on. Before purchasing gas, make note of how many miles you have driven since writing down your first reading. Subtract the new odometer by the original reading, and divide that number by the number of gallons you just purchased.

The easiest way to calculate your MPG is to use this tool.

Tool to calculate miles per gallon for your road trip
Tool to calculate miles per gallon for your road trip

Plan your route & calculate total mileage

Calculate the total distance or average amount of miles you will travel during the span of your road trip. Using an atlas or Google Maps, start with your beginning and ending destination. Then, add in additional miles for stops, side trips, and detours that you plan on taking. Even though your itinerary is likely to change, it’s wise to over budget in the beginning, just in case. Be sure when you are calculating your miles, you are basing it on the route you actually plan on taking.

Add up your trip cost

Finally, it’s time to add up the total trip cost; the cost of gas that is. To do this, start by taking the total distance of your trip and then divide that number by your vehicle's miles per gallon, to estimate the number of gallons your trip will need. Next, multiply that number by the current gas price. The end result will be the estimated cost of gas for your road trip.

Estimating highway miles

As mentioned before, driving in the city and on highways is going to cause your MPG to fluctuate, altering the amount of money you will spend on gas. To help you better understand how to properly estimate the difference, use this formula:

Calculate road trip gas

Estimated cost of trip = ((City miles/City MPG) + (Highway Miles/Highway MPG)) x $ Gas/Gallon

Reducing gas costs for your trip

When planning a road trip, saving small amounts of money here and there can really go a long way and add up in the long run. There are various things you can do that are simple and easy, but will reduce the cost of gas during your road trip:

  • While on the road be sure to use cruise control when possible,
  • avoid engine idling,
  • avoid hauling excessive weight,
  • watch the speed limit,
  • and reduce rapid acceleration and braking.

Calculating the cost of gas is a simple step to take in advance to ensure a happy and successful trip. We hope you use this guide when planning your next road trip and that it inspires you to be properly prepared financially when budgeting costs for your adventure.

Road Trips > Cheap Road Trip Tips > Cost of Gas for a Road Trip

Steps to Estimate The Cost Of Gas For A Road Trip Infographic
How To Estimate The Cost Of Gas For A Road Trip Infographic

About the Author

Ali Sullivan

Hi I'm Ali Sullivan. I have been traveling full time for the past 5 years and have been to over 30 countries on 4 different continents. During this time I worked overseas in multiple countries as well as online and transitioned fully to online work in 2020. Find me here on Instagram.