How this works
The maths is simple and honest: distance times consumption gives the litres used, and litres times price gives the cost. I pre-filled the price with the June 2026 national average, but since it changes weekly I left it fully editable — type your station’s price for an accurate number. Everything is computed in your browser.
- 1
Litres used
litres = distance (km) × consumption (L/100km) ÷ 100. A 200 km trip at 6 L/100km uses 12 litres.
- 2
Fuel cost
cost = litres × price per litre. Those 12 litres at €1.77/L cost €21.24.
- 3
Round trip and repeats
Turn on “round trip” to double the distance, and set how many times you make the trip (e.g. work days in a month).
Frequently asked
Which fuel price should I use?
The price you will actually pay at the pump. The values I pre-filled are indicative national averages from June 2026 — a starting point only, since prices change weekly and vary by station and district. Clear the field and type your station’s price. The official daily averages are at DGEG.
How do I know my car’s consumption?
It is on the spec sheet and in adverts as “L/100 km” (litres per hundred kilometres). Your trip computer also shows the average. Note: real-world consumption is almost always higher than the official WLTP figure — in town, with A/C, or at motorway speed, add 1 to 2 L/100 km.
Does this include tolls?
No. This tool calculates fuel only. In Portugal tolls can add up a lot on a long trip — add them separately when planning your total cost.
How do I split the cost between people?
Work out the trip’s total cost (turn on “round trip” if relevant) and divide by the number of occupants. For example, €40 of fuel between 4 people is €10 each. That is the usual basis for settling up on shared rides.
Can I use it for diesel, petrol or LPG?
Yes. The formula is the same for any liquid fuel sold by the litre — only the price per litre and the car’s consumption change. Pick the type in the shortcuts to pre-fill an indicative average price, or type your own.
DISCLAIMER
The pre-filled prices are indicative national averages (June 2026) and are only a starting point — the real price changes weekly and varies by station. Always edit it to your station’s. The result covers fuel only: it excludes tolls, wear, insurance and other costs. Check official prices at DGEG.