How to Calculate Gas Needed for a Trip
As the cost of gas continues to rise, the gas you put in your car for your vacation is becoming more and more of an issue as you budget for your next trip. Calculating the amount of gas you will need for your trip is not too difficult, but it does require a little bit of forward thinking. By taking the time to plan for the amount of gas you will need ahead of time, you will be better able to budget money for the more entertaining aspects of your vacation, such as your park tickets and dinner out.
Things You'll Need
 Calculator
 Notepad

Start by figuring out the average miles per gallon that your vehicle gets. Write down your mileage the next time you fill up your vehicle. When you have to fill up again, figure out how many miles you traveled. Divide this by the number of gallons you had to purchase, and you will know your average miles per gallon.

Figure your average miles per gallon for your next two fill ups, and then average these three amounts. This will give you a good estimate as to the amount of gas you use on average over a variety of road conditions.

Use a map or an online map program to determine how far you will be traveling to your destination. Be sure to account for any stops along the way, such as a hotel stay halfway between your home and your destination.

Add a few extra miles to the total, because you will need to stop for gas and may have to take a detour for road construction as you make your trip.

Divide the total miles by the average miles per gallon that your vehicle gets. This is the amount of gas you will need to purchase for your trip.
Tips & Warnings
 To find out the approximate cost of your trip, go online to determine the cost of gas in the areas you will be traveling. Multiply this cost by the total number of gallons you will need to get an estimate of cost.
 If you are renting your vehicle, you can go online to find the average gas mileage of the make and model of vehicle you will be renting.
 Never start a trip without calculating the cost. You want to make sure you can afford to have fun once you arrive at your destination.
Resources
 Photo Credit Mike Johnson