Fuel cost calculator

This fuel cost calculator shows what one trip costs in fuel or electricity — and how that adds up over a month and a year. You enter the consumption and the price yourself; the calculation runs entirely in your browser and nothing is stored or sent anywhere.

This calculator needs JavaScript because the calculation runs entirely in your browser – so your inputs never leave your device. A worked example is shown further down this page.

How this calculator works

A trip's cost comes from distance, consumption and price: cost = distance ÷ 100 × consumption per 100 km × price per unit. The calculator is unit-neutral — you can work in litres (l/100 km, price per litre) or in electricity (kWh/100 km, price per kWh); the maths is identical.

"Return trip" doubles the one-way distance. You can split the cost across several people in a car-share. In the optional commute mode the calculator scales the per-trip cost by your working days per year to yearly and monthly figures (year = cost per trip × working days, month = year ÷ 12). The optional comparison scenario puts two vehicles or drivetrains (e.g. an electric car against a petrol one) side by side. Distances are metric (km) and consumption is per 100 km.

Formula and variables

Amount=Distance / 100 × Consumption

Cost per trip=Amount × Price

Cost per year=Cost per trip × Working days

Distance: distance travelled per trip in km (doubled for a return trip)
Consumption: consumption per 100 km (litres or kWh)
Price: price per litre or per kWh (your input)
Amount: fuel or energy used per trip

Worked examples

Example: an electric-car commute shared by two

Example inputs
Distance (one way)	30 km
Return trip	yes (60 km)
Consumption	18 kWh/100 km
Price	0.40 per kWh
People	2
Working days per year	215

Example results
Cost per trip	€4.32
Cost per person	€2.16
Cost per year	€928.80

Amount per trip = 60 / 100 × 18 = 10.8 kWh; cost per trip = 10.8 × 0.40 = €4.32. Split across 2 people that is €2.16 each. Over 215 working days: €4.32 × 215 = €928.80 a year. Price and consumption are example assumptions.

Assumptions

Consumption and price stay constant within the scenario (your assumption — real figures vary).
The price is your input, not a live daily price.
In commute mode exactly one trip is counted per working day.

Limitations of this calculator

Real consumption depends on route, driving style, load and weather.
No fuel or electricity price data, and no petrol-station or tariff recommendation.
No tax treatment of commuting (no mileage allowance — that is a tax topic).

Frequently asked questions

Can I use it for an electric car?

Yes. Enter consumption in kWh per 100 km and the price per kWh — the formula is the same. Use the comparison scenario to put an electric car and a petrol one side by side.

Why do I enter the price myself?

This calculator deliberately uses no daily prices. That keeps the result transparent and lets you work with your actual price or one you assume.

Does this send my trip details anywhere?

No. The calculation runs entirely in your browser. Your entries are not stored and are not sent to a server.

Sources and further reading

Official and independent sources on this topic. The links open each website in a new tab; no content is loaded from them into this page.

Fuel economy and fuel cost informationU.S. Department of Energy / EPA (fueleconomy.gov)Official information on estimating fuel use and cost. Background to the consumption and price inputs; no live local prices.
Cost of running a carMoneyHelper (UK Money and Pensions Service)Consumer overview listing fuel among the running costs of a car. No live fuel prices.

Spotted an error in the calculation or the text?

If you notice something that is wrong or unclear: let us know via the contact page. We review every report.

Last reviewed: 01/08/2026 · All calculations run in your browser – inputs are not stored. ·How we check our calculators