Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total fuel cost
$144.00
Cost per person
$72.00
Gallons needed
40.0
Total miles driven
1,200
Fuel cost per mile
$0.120
Approximate fill-ups (14 gal tank)
2.9
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter trip distance (miles).
- 2Enter fuel economy (mpg).
- 3Enter gas price per gallon ($).
- 4Enter trip type.
- 5Enter people splitting the cost.
- 6Read your total fuel cost on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Highway speed matters more than people expect: most cars lose 10–15% fuel economy going from 65 to 80 mph, which can add a full tank on a long drive.
Worked example
Using the values the calculator loads with:
Inputs
- Trip distance (miles): 600
- Fuel economy (MPG): 30
- Gas price per gallon: 3.6 $
- Trip type: Round trip
- People splitting the cost: 2
Results
- Total fuel cost: $144.00
- Cost per person: $72.00
- Gallons needed: 40
- Total miles driven: 1,200
- Fuel cost per mile: $0.12
- Approximate fill-ups (14 gal tank): 2.9
What each field means
Inputs
- Trip distance (miles)
- The trip distance (miles) used in the calculation. Starts at 600 so you have a working example on load.
- Fuel economy (MPG)
- The fuel economy (mpg) used in the calculation. Starts at 30 so you have a working example on load.
- Gas price per gallon ($)
- The gas price per gallon used in the calculation, measured in $. Starts at 3.6 $ so you have a working example on load.
- Trip type
- Pick the option that matches your situation — the maths changes per option. Choices: One way, Round trip.
- People splitting the cost
- The people splitting the cost used in the calculation. Starts at 2 so you have a working example on load.
Results
- Total fuel cost
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost per person
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Gallons needed
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total miles driven
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Fuel cost per mile
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Approximate fill-ups (14 gal tank)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the road trip gas cost calculator work?
Highway speed matters more than people expect: most cars lose 10–15% fuel economy going from 65 to 80 mph, which can add a full tank on a long drive. The underlying maths is: Cost = Distance ÷ MPG × Price per gallon.
What do I need to enter?
5 values: trip distance (miles), fuel economy (mpg), gas price per gallon, trip type, and people splitting the cost. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the total fuel cost result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Gas Trip Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/gas-trip-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/gas-trip-cost" target="_blank" rel="noopener">Gas Trip Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Gas Trip Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/gas-trip-cost) (2026).