How is the trip cost calculated?

The fuel used is the distance divided by your efficiency, and the cost is that fuel multiplied by the price per unit.

What if my car's economy is in litres per 100 km?

Convert it to distance per unit first: 100 divided by your litres-per-100-km figure gives km per litre. For example, 6.7 L/100 km is about 15 km per litre.

Does it handle miles and gallons?

Yes. Enter miles as the distance, miles per gallon as the efficiency, and a price per gallon. Just keep the units consistent.

Is this one way or round trip?

It uses the distance you enter. For a round trip, enter the total there-and-back distance.

Which currency does it use?

The currency follows the site language. The fuel math is identical in every market.

Can I share a calculation?

Yes. Use Share to copy a link that reopens the calculator with the same distance, efficiency, and price.

Fuel cost calculator

Enter the trip distance, your vehicle's fuel efficiency (distance per unit of fuel), and the price per unit. The calculator shows the trip cost and the fuel used as you type.

Use it to estimate what a journey costs in fuel, plus how much fuel it takes and the cost per unit of distance.

Trip cost

$60.00

Fuel used: 33.3 units
Cost per distance: $0.12

The result updates as you type. It shows the total trip cost, the fuel used, and the cost per unit of distance.

How does it work?

Use consistent units: if efficiency is km per litre, distance is in km and price is per litre. The fuel used is distance divided by efficiency.

Fuel cost formula

\text{cost} = \frac{\text{distance}}{\text{efficiency}}\times \text{price}

distance: Trip distance.
efficiency: Distance per unit of fuel (e.g. km/L or mpg).
price: Price per unit of fuel.

A 500 km trip at 15 km per litre uses about 33.3 litres; at 1.80 per litre that is about 60.00.

Method & sources

Fuel efficiency is distance per unit of fuel, such as km per litre or miles per gallon. Distance, efficiency, and price use consistent units that you choose. Fuel used is the distance divided by the efficiency; cost is fuel used times the price.

Sources

Where this method comes from — use these references to understand the formula, assumptions, and limits.

Gasoline and diesel fuel update — U.S. Energy Information Administration, verified 2026-06-10

How we calculate

Fuel efficiency is distance per unit of fuel, such as km per litre or miles per gallon.
Distance, efficiency, and price use consistent units that you choose.
Fuel used is the distance divided by the efficiency; cost is fuel used times the price.
A constant efficiency is assumed for the whole trip.
Tolls, wear, traffic, and load are not included.

Rounding

Costs are rounded to two decimals and fuel used to two decimals for display. The calculation uses full precision.

What this calculator does

The fuel a trip uses is the distance divided by your vehicle's efficiency, and the cost is that fuel times the price per unit. This calculator works in whatever units you use, as long as they match: kilometres with km per litre and a price per litre, or miles with miles per gallon and a price per gallon.

How to use it

Enter the trip distance.
Enter your fuel efficiency as distance per unit of fuel.
Enter the price per unit of fuel.
Read the trip cost and fuel used below.

A worked example

A 500 km trip in a car doing 15 km per litre uses about 33.3 litres. At 1.80 per litre, the trip costs about 60.00 — roughly 0.12 per km.

Keep your units consistent

The calculator doesn't assume a unit system. If your efficiency is km per litre, enter the distance in km and the price per litre. If it's miles per gallon, use miles and a price per gallon. Mixing units gives a wrong answer.

Common mistakes

Entering litres per 100 km in the efficiency field. This field expects distance per unit of fuel, not fuel per distance.
Mixing miles with a per-litre price, or km with a per-gallon price.
Forgetting the trip is one way — double the distance for a round trip.

When it's useful

Budgeting a road trip, splitting fuel costs with passengers, or comparing the running cost of two vehicles.

FAQ

How is the trip cost calculated?: The fuel used is the distance divided by your efficiency, and the cost is that fuel multiplied by the price per unit.
What if my car's economy is in litres per 100 km?: Convert it to distance per unit first: 100 divided by your litres-per-100-km figure gives km per litre. For example, 6.7 L/100 km is about 15 km per litre.
Does it handle miles and gallons?: Yes. Enter miles as the distance, miles per gallon as the efficiency, and a price per gallon. Just keep the units consistent.
Is this one way or round trip?: It uses the distance you enter. For a round trip, enter the total there-and-back distance.
Which currency does it use?: The currency follows the site language. The fuel math is identical in every market.
Can I share a calculation?: Yes. Use Share to copy a link that reopens the calculator with the same distance, efficiency, and price.

Related calculators

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<p>Calculator from <a href="https://wisecalcs.com/en/finance/fuel-cost-calculator">WiseCalcs</a></p>