About the Trip Cost Calculator
A road trip often costs more than the petrol alone, but fuel is the biggest line and the one most people want to know before they leave. This calculator takes the one-way distance, whether you are going there and back, your car's fuel economy and the price of fuel, and works out how much fuel you will use and how much it will cost. Add tolls and parking, and say how many people are sharing, and you get the total cost and the cost per person. It works in kilometres with litres, or miles with US gallons.
Updated October 2026
How to use the Trip Cost Calculator
- 1Choose kilometres and litres, or miles and gallons.
- 2Enter the one-way distance and pick one way or round trip.
- 3Enter your car's fuel use in L/100 km or miles per gallon.
- 4Enter the fuel price and any tolls or parking.
- 5Say how many people share the cost and read the total.
Getting a realistic estimate
The official fuel economy of a car is measured in test conditions. In real driving, hills, traffic, cold weather and heavy luggage all push the figure up. A good approach is to use the average from your own trip computer over a similar journey, and to add 10 percent if you are unsure.
Check prices along your route if you can. Motorway services are often much more expensive than fuel in town.
Ways to cut the cost
- Keep a steady speed and avoid hard acceleration.
- Remove roof racks and unneeded luggage.
- Keep tyres at the recommended pressure.
- Share the trip with passengers and split costs.
- Plan to refuel where prices are lower.
Related tools
The Mileage Calculator works out reimbursement per mile, the Fuel Economy Calculator converts between mpg and litres per 100 km, and the Distance and Speed calculators help plan the timing. The Tip Calculator splits restaurant bills along the way.
Features
- Metric and US units
- One-way and round trips
- Tolls, parking and other costs
- Cost per person
- Cost per kilometre or mile
- Currency symbol of your choice
Frequently asked questions
How do I calculate the fuel cost for a trip?
Work out the fuel you will use, then multiply by the price. With 7.5 L/100 km, a 320 km trip uses 24 litres, and at 1.80 per litre that costs 43.20. In miles per gallon, divide the miles by the mpg to get gallons.
Where do I find my car's fuel economy?
Use your car's trip computer, which shows the real average, or divide the distance on a full tank by the fuel you put in. The manufacturer's figure is usually better than real driving, so add 10 to 20 percent if you drive fast or carry a load.
What else should I include in a trip budget?
Tolls, parking, ferries, congestion charges, food, accommodation and a share of vehicle wear and tyres. Adding a standard mileage rate, such as the tax-authority rate in your country, gives a fuller cost per mile.
How do I split the cost between passengers?
Divide the total shared costs by the number of people in the car, including the driver. Many groups split fuel and tolls equally and leave insurance and wear out of it. The calculator does the even split.
Does speed affect fuel use?
Yes. Fuel use rises quickly above about 90 km/h (55 mph). A trip at 120 km/h can use 20 percent more fuel than the same trip at 100 km/h. Roof boxes, headwinds and air conditioning also add to the use.
Can I use it for an electric car?
You can use it by treating the energy per 100 km in kWh as the fuel use and the electricity price per kWh as the fuel price. Works for metric units only: enter kWh/100 km and price per kWh.