Calculate Your Gas Usage

Screenshot of Gasoline Calculator

Here is the spreadsheet I promised. It is called the Out of Debt Again Gasoline Calculator v.1

As long as you input the correct numbers you can get a pretty accurate answer to the following questions about your gasoline usage in the past, present and future.

  1. How many miles per gallon is my vehicle getting?
  2. How much does it cost me to drive one mile in my vehicle?
  3. How much will it cost me to drive xx miles in my vehicle?
  4. How much will it cost me to drive xx miles for xx days in my vehicle?
  5. How much money will I spend on gas if the price goes up to xx?
  6. How much will I spend on gas for one month’s worth of driving?

The spreadsheet is in Microsoft Excel format. It does work with OpenOffice which is a free productivity suite of programs.

My spreadsheet is simple to use. I’ve locked certain cells so you can’t accidentally mess up the formulas.

TOP PORTION: Calculate Miles Per Gallon

Here’s how to use the top portion: Calculate how many miles per gallon your vehicle gets:

Screenshot Gas Calculator

  1. Fill your tank with gas and enter the odometer reading in the first box.
  2. For the best average of usage, wait until your tank is near empty until you fill it up again. Now enter the odometer reading in the second box.
  3. In the third box, enter how many gallons of gas. You can put the exact number. 16.75 or 14.34 or whatever it is.
  4. In the fourth box, which is pink, type in what the gasoline cost, including the last nine at the end.

Now you will see the last four numbers have automatically calculated several things for you. How much this tank of gas cost (but you already knew that!), how many miles you drove from Fillup 1 to Fillup 2, the blue box tells you how many miles per gallon your vehicle got on this tank, and the last line calculates how much gasoline costs you to drive per mile.

This is very handy to know. For example, if you shop grocery stores by the sale ads, and you have decided to drive an extra five miles to say $1.00 on an item, with the calculations on the image above, you are spending $0.22 per mile. For the round trip, you’ll be spending $2.20, so it would cost you less to buy the item at the closer store.

I use this portion of the calculator to convince my family to cut down on trips to the store that are possibly unnecessary (which we are actually pretty good at that already). For example, when you consider the nearest grocery store is 8 miles away from us, is it worth the extra $3.52 to buy a can of chocolate syrup just because someone’s craving it?

BOTTOM PORTION: Estimate Cost of Gasoline

Now for the second part of my calculator: Estimate Your Future Cost for Gasoline

Screenshot Gasoline Calculator

  1. The bottom portion uses information from the top portion. I left Line 1’s box blank in case you already know your MPG without going through the top portion. So if you know how many miles per gallon your vehicle currently gets, put that number there. Otherwise, guesstimate or do the top portion first.
  2. Enter the cost of gasoline into the pink box in the top portion, and this box will automatically fill. Put in the current price, or estimate on the high side by putting in a higher amount.
  3. Enter how many miles you are planning to drive. I use this portion to estimate how much money we’ll need to set aside for gasoline for two weeks at a time. I enter 100 miles, which is my round trip commute. If you know you’re going on a trip that’s 2000 miles, just enter 2000. Then enter 1 in the next box.
  4. In the next box, enter how many days. I work Monday through Thursday, so I count how many days I’ll be driving into the office and enter that number. Then I can get an idea of how much money I’ll need to hold back for gasoline.

Remember that figuring your MPG can help you detect a problem with your vehicle – if you calculate your mileage and it’s always 18-19, but suddenly it drops to 16, there is usually something up. It could be that your tires are low, your air filter is dirty, you are carrying more weight than normal, or bad gas just to name a few things.

This post was included at The 156th Carnival of Personal Finance! Thank you Prime Time Money for the hard work of hosting this event, and including my post!

OUT OF DEBT AGAIN is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to AMAZON.COM. OUT OF DEBT AGAIN is an affiliate for several companies and may be compensated through advertising and marketing channels. This post may contain affiliate links.

11 thoughts on “Calculate Your Gas Usage

  1. Thanks, Mrs. Accountability, for the Excel spreadsheet.

    We just filled up yesterday, so we won’t be putting the calculator through its paces for several days, yet.

    We already figure out our mileage at each fill-up; however, I’ve only recently started looking at what our daily trips cost us. The calculator will certainly help in that department. Thanks, again.


  2. Kathryn, thank you for commenting! I hope you will find it helpful. Let me know how it works out, once you get a chance to test it. If you already know your MPG, you can use the bottom portion, which will help you calculate your daily trips! Have a wonderful day!


  3. Hi, Mrs. A. — Thanks for dropping by Funny and leaving the great comment!

    Just to let you know…I spotted the gas usage spreadsheet at the CoPF and linked to it in this week’s “Moments of Fame.” Love it!! Don’t know how many of my millions of doting fans read that feature, but hey…at least it’s a link!


  4. One of the things that I’m using now is FuelFrog ( It integrates with Twitter, although you aren’t required to use Twitter, but gives you all sorts of trend information as well – this, along with your spreadsheet can come in very handy! Thanks!!


  5. Hi Brack, I haven’t heard of fuelfrog – I’ll be sure to check it out! Let me know how you like the gasoline calculator spreadsheet. I’ve been using a simplified version of it for the past few years, but I worked to make it better over the past couple of weeks and I am really liking how it works! Thanks for posting! 🙂


  6. Nice spreadsheet, Mrs A.
    I have a slightly different one, that calculates the incremental cost when gas jumps from say $2.79 per gallon to $3.19 per gallon, and averages it out for our “fleet” of two vehicles.


    Mrs. Accountability Reply:

    @101 Centavos, thanks! Glad you liked it. I have another one that I use for Mr. A’s business which holds his mileage and calculates the mileage per trip depending which vehicle he used. I love Excel. 🙂


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