Fuel Cost Calculator
What a journey actually costs in fuel — and what the same trip costs you over a month of repeating it.
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How it works
Fuel economy is quoted three different ways around the world, and two of them run in opposite directions: higher is better for km/l and mpg, lower is better for l/100km. Pick the one your car reports and the calculator normalises it.
Splitting the cost between passengers is where car travel usually wins on price. The per-person figure is the one to compare against a train or plane ticket, not the total.
Fuel used = distance ÷ efficiency · Cost = fuel used × price per unit
- Efficiency — how far the vehicle travels per unit of fuel, in your chosen convention
- Price — the cost of one litre or gallon, matching the efficiency unit
- Return trip — doubles the distance, which is easy to forget when budgeting
Worked example
A 420 km trip at 16 km/l with fuel at 105 per litre, three people sharing
Inputs
Results
The return journey doubles this to 5,513 — worth checking before comparing against a return train fare.
Frequently asked questions
Which efficiency unit should I pick?
Whichever your car displays. km/l is common across South Asia, l/100km across Europe, and mpg in the US and UK — though the US and UK gallons differ, so choose the right one of the two.
Why is my real consumption worse than the quoted figure?
Manufacturer figures come from controlled test cycles. City driving, air conditioning, a full load and higher speeds all cut real-world economy, often by 10–25%. Use your own measured figure if you have one.
Does this cover the full cost of driving?
No — fuel only. Depreciation, tyres, servicing, insurance and tolls all add up, and on a long trip they can rival the fuel bill. This is the marginal cost of the journey, not the total cost of the car.
Is my data sent anywhere?
No. The calculation runs entirely in your browser. Nothing you type is transmitted to us or stored.
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