# How much gas will you use on your road trip?

Calculating the Cost of Gas for a Road Trip

Fuel costs for long road trips can be startlingly high, especially if you don't know what to expect ahead of time. Luckily, calculating the cost of gas for your road trip is a matter of simple arithmetic, and there are even several Web sites that will do the math for you.

Before you can determine the cost of gas for your road trip, you need to figure out your vehicle's gas mileage. Typically, this number is listed in your owner's manual or can be found on the Internet. If not, you can calculate it yourself by first filling up the tank and resetting the trip odometer. Once you've used at least half of the gasoline in the tank, fill the tank again and note how much fuel you put in the car, as well as the mileage on the odometer. Then divide the number of miles by the gallons of fuel to get your vehicle's miles per gallon (MPG) rating. For example, if you traveled 250 miles on 10 gallons of gasoline, your car's MPG rating is 25.