FinToolSuite

Fuel Cost Calculator

Updated April 17, 2026 · Utilities · Educational use only ·

Trip fuel cost in seconds.

Calculate fuel cost for a trip. Enter distance, MPG, and fuel price. Enter distance miles and mpg uk gallons for an instant result.

What this tool does

This tool calculates trip fuel cost given distance, fuel efficiency in MPG gallons), and fuel price per litre. Shows total fuel cost, litres used, and cost per mile.


Enter Values

Formula Used
Distance miles
Miles per gallon
Price per litre

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Calculations, display, or translation — let us know.

Disclaimer

Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.

Calculate the fuel cost of any trip given distance, fuel efficiency (MPG), and fuel price per litre. Useful for budgeting long journeys, comparing transport options, or tracking cost per mile.

300-mile round trip at 40 MPG with 1.50/litre petrol: needs 34 litres at 51 total - 17p/mile. Compare to rail at 45-80 or EV charging at 12-20 for the same trip. Numbers reframe transport decisions.

The tool uses gallons (4.546 litres) - the standard for MPG figures. gallons are 3.785 litres - adjust accordingly if using MPG.

Quick example

With distance of 300 and mpg of 40 (plus fuel price per litre of 1.5), the result is 51.14. Change any figure and watch the output shift — it's often more useful to see the pattern than to memorise the formula.

Which inputs matter most

You enter Distance (Miles), MPG Gallons), and Fuel Price per Litre. Frequency and unit price pull the total in different directions. The biggest surprise for most people is how small recurring amounts compound into large annual figures — that's where this calculation earns its keep.

What's happening under the hood

Litres needed = (distance × 4.546) / MPG. Cost = litres × price per litre. Uses gallon conversion (1 gallon = 4.546 litres). The formula is listed in full below. If the number looks off, you can retrace the calculation by hand — that's the point of showing the working.

What the bill doesn't show

Standing charges, discounts, and usage tiers all blur the effective rate. The calculation here backs out the total so you're comparing apples to apples across providers, regardless of how each one packages the price.

What this doesn't capture

Usage varies month-to-month; tariffs change; discounts come and go. The figure here is a clean baseline — your actual annual bill will fluctuate around it. Use the calculation to benchmark providers, not as a prediction of a specific bill.

Example Scenario

300 miles miles at 40 MPG × £1.5 £/L = $51.14.

Inputs

Distance (Miles):300 miles
MPG Gallons):40
Fuel Price per Litre:1.5 £
Expected Result$51.14

This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.

Sources & Methodology

Methodology

Litres needed = (distance × 4.546) / MPG. Cost = litres × price per litre. Uses gallon conversion (1 gallon = 4.546 litres).

Frequently Asked Questions

gallons?
Gallon = 4.546 litres. gallon = 3.785 litres. MPG values are 20% higher than equivalents for the same efficiency. This calculator uses gallons - adjust by multiplying MPG by 0.833 if using MPG figures.
Does MPG vary?
Yes significantly. Motorway 50-60 MPG typical for efficient cars. City 25-35 MPG. Mixed driving averages quoted values. Use real-world MPG from your trip computer rather than official figures (usually 10-20% higher than real).

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