Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Trip cost
$43.75
Fuel used
12.50
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter trip distance.
- 2Enter units.
- 3Enter efficiency.
- 4Enter fuel price.
- 5Read your trip cost on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Estimate the fuel cost of a trip from distance, vehicle efficiency, and gas price.
Worked example
Using the values the calculator loads with:
Inputs
- Trip distance: 350
- Units: Miles / mpg / $ per gallon
- Efficiency: 28
- Fuel price: 3.5
Results
- Trip cost: $43.75
- Fuel used: 12.5
What each field means
Inputs
- Trip distance
- The trip distance used in the calculation. Starts at 350 so you have a working example on load.
- Units
- Pick the option that matches your situation — the maths changes per option. Choices: Miles / mpg / $ per gallon, Km / km per liter / $ per liter.
- Efficiency
- The efficiency used in the calculation. Starts at 28 so you have a working example on load.
- Fuel price
- The fuel price used in the calculation. Starts at 3.5 so you have a working example on load.
Results
- Trip 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.
- Fuel used
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the fuel cost calculator work?
Estimate the fuel cost of a trip from distance, vehicle efficiency, and gas price.
What do I need to enter?
4 values: trip distance, units, efficiency, and fuel price. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the trip 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. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Fuel Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/fuel-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/fuel-cost" target="_blank" rel="noopener">Fuel Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Fuel Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/fuel-cost) (2026).