Fuel cost calculator: total trip cost and cost per person
Estimate petrol or diesel trip costs from your own distance, consumption and prices, then split the total. Include tolls and parking yourself: the calculator does not look up routes or current tariffs.
Your journey
The calculator processes your entries in this browser, without sending them to a calculation service or saving them. Reloading clears your entries.
Compare routes and parking choices fairly
For each option, enter its own distance and fees and calculate again. A cheaper car park may mean a detour or extra public transport fares: put those shared fares under other costs. A route without tolls can use more fuel. Compare the complete total as well as travel time, walking distance and accessibility.
Choose realistic inputs
Use your recent measured consumption if possible. Traffic, cold starts, gradients, load and roof boxes can change it. The return checkbox assumes the same route and consumption; for a different return route, enter the combined distance and leave it unchecked, or calculate the legs separately.
This tool covers petrol and diesel. It does not estimate EV charging, locate the cheapest fuel, calculate toll tariffs or verify parking availability. For a plug-in hybrid, the fuel calculation alone leaves out charging costs. Verify toll and parking conditions with the operator before travel.
How the calculation works
For litres per 100 km, fuel needed = total distance in km × consumption ÷ 100. Fuel cost = litres × price per litre. The shared total adds fuel, tolls, parking and your other costs. It excludes insurance, depreciation and maintenance unless you include them yourself.
For mpg, fuel needed = distance in miles ÷ mpg × litres per gallon. A UK gallon is 4.54609 litres; a US gallon is 3.785411784 litres. A mile is 1.609344 km. UK and US mpg are not interchangeable.
Worked example: a day trip shared by four people
Drive 150 km each way at 6 L/100 km, with fuel at €1.80/L. The 300 km return journey uses 18 L, costing €32.40. Add €12 in return tolls and €8 for parking: €52.40 total, or €13.10 each for four paying people. These are illustrative inputs, not prices for a destination.
Before you calculate
Do I count the driver?
Count everyone who will pay a share, including the driver if they are contributing. Use 1 if you only want the whole budget. The split is equal; it is not a legal mileage reimbursement calculation.
Can I enter the whole route distance?
Yes. Enter the total distance and leave the return box unchecked. Checking it doubles the distance you entered and the fuel estimate, not the extra fees.
Does changing the currency convert prices?
No. Convert each expense into one chosen currency before entering it, including foreign tolls and parking. The result uses only the numbers you supply.
Build a trip with separate currencies and legs
Use one line for each fuel-price or currency area. The exchange rate is the number of units of the total currency for one local unit: for example, a manually chosen GBP→EUR rate of 1.15 means £1 becomes €1.15. It is an assumption, not a live quote.
Your entries stay in this browser tab. Nothing is sent to Osmopark.
Worked example and its assumptions
- Total currency
EUR
- One leg per line: km; L/100 km; fuel price/litre; EUR/GBP/USD; exchange rate; known fees
300;6;1.70;EUR;1;12 150;6.5;1.50;GBP;1.15;5
| Leg | Local currency | Fuel, local currency | Known fees, local currency | Rate to total currency | Total |
|---|---|---|---|---|---|
| 1 | EUR | 30.6 | 12 | 1 | 42.6 |
| 2 | GBP | 14.63 | 5 | 1.15 | 22.57 |
Total (EUR): 65.17
Maximum six legs. Include the return leg explicitly. Fees must be known amounts in that leg’s currency; a missing fee cannot be treated as free. The total covers entered items only. Use rate 1 when local and total currencies match.
Build a budget range from your own assumptions
The first row combines low consumption and low fuel price; the second combines both high assumptions. This is a sensitivity envelope, not a probability forecast. Enter all amounts in the same currency.
Your entries stay in this browser tab. Nothing is sent to Osmopark.
Worked example and its assumptions
- Distance (km)
600
- Low consumption (L/100 km)
5.5
- High consumption (L/100 km)
7
- Low fuel price per litre
1.6
- High fuel price per litre
1.9
- Known fixed costs
25
| Litres | Fuel cost | Known fixed costs | Total |
|---|---|---|---|
| 33 | 52.8 | 25 | 77.8 |
| 42 | 79.8 | 25 | 104.8 |
Keep unpriced items outside the total and identify them before setting your spending limit. A range cannot protect against an omitted ferry, hotel or parking charge.
Check the rules and costs for your route
MPG to L/100 km converter: UK and US gallons · Driver tools and calculators
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Calculation method updated on 30 October 2026. Report an error