# How to estimate fuel cost before a road trip
A useful road trip fuel estimate needs four facts: the one-way distance, the vehicle consumption, the pump price you choose, and the number of travelers sharing the bill. This calculator doubles the route when you select round trip, calculates fuel from the vehicle rate, and divides the result by the passenger count.# The fuel cost formula
| Step | Calculation | What it tells you |
|---|---|---|
| Total distance | One-way distance x 2 for a return trip | How far the vehicle actually travels |
| Fuel used | Total distance x consumption / 100 | Litres needed for the route |
| Total cost | Fuel used x your manual price | The estimated fuel spend |
| Cost per person | Total cost / passengers | A fair share for the group |
Use a current manual price
Fuel prices vary by station, country, fuel grade, and date. Enter the price you expect to pay and treat the result as a planning estimate, not a live quote.# Metric and imperial fuel figures
Metric mode uses kilometres and litres per 100 kilometres. Imperial mode shows miles and miles per gallon while preserving the same physical trip underneath. Switching units does not change the estimated cost.- Add a small buffer for detours, traffic, and searching for parking.
- Use the consumption figure from your own vehicle rather than a best-case brochure value.
- For mixed cars or multiple fuel stops, calculate each leg separately and add the results.