How to Calculate Gas Mileage & Easy MPG Calculator

how to calculate gas mileage

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How much gas does your RV or car actually use? Whether you drive a large RV or a small car, you’ll want to know your vehicle’s gas mileage. Once you know your vehicle’s miles per gallon, you’ll be able to accurately determine how much any road trip will cost. Here’s how to calculate gas mileage and a handy calculator to do the math for you.

Road Trip Gas Cost Calculator – Find out how much gas will cost for your next road trip. For cars and RVs.

How to Calculate Gas Mileage (miles per gallon).

Hands on time needed(plus drive time): 20 minutes

How to calculate your car or RV’s gas mileage (miles per gallon).

  1. Fill your car or RV gas tank completely.

  2. Set a trip odometer or write down your starting mileage.

  3. Drive normally until you need to refuel.

  4. Refuel and fill your gas tank completely. Write down exactly how many gallons of gas you added to your tank.

  5. Check your trip odometer and write down how many miles you have driven. Do this while you are still at the gas station.

  6. To calculate your MPG divide your miles driven by gallons of gas added to your tank. Or, just enter your miles driven and gallons of gas used in our gas mileage calculator.

Gas Mileage Calculator (MPG)

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Miles per gallon (MPG) calculator
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Once you calculate your car or RV’s gas mileage over a short trip, you may want to keep tracking your miles driven and gallons of fuel used over a longer period of time to get a more accurate average. Of course, there are many things that impact how much gas you will use on any given trip. For example, driving through mountains will use far more gas than driving along a flat road. So, you’ll want to get a good average over a variety of driving conditions.

Calculating Gas Mileage When Towing

It’s important to note that when you are towing an RV, like a travel trailer or fifth wheel, your mileage will be different than it is when you are just driving your tow vehicle. When you calculate your mileage, make sure that you are doing it for miles driven and gas used while you are towing.

Thanks for stopping by. I hope you enjoyed the gas mileage calculator!

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We’ve been full-time RVers since 2012. Over 127,000 miles and 47 states later, we are still towing our home around the United States.

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