How to split fuel and car costs on a road trip

Add up the fuel (distance × consumption × price, or every fill-up receipt if you start and finish with a full tank), add a small amount per kilometre for wear on the owner's car, put tolls, ferries and parking in the same pot, and split the total equally between everyone in the car, owner included. Anyone who's only along for part of the way pays for the legs they were in the car.

For four people driving from Stockholm to Göteborg and back for a weekend, that comes to about 470 kr each. The workings are below.

The fuel formula

Fuel cost = distance in km × litres per 100 km ÷ 100 × price per litre.

Swedish drivers often quote consumption in litres per mil (1 mil is 10 km), so 0.65 l/mil is the same as 6.5 l/100 km. Use the trip computer's real average rather than the brochure figure. A full car with a roof box at motorway speed uses noticeably more than the brochure promises.

Stockholm to Göteborg is about 470 km, so 940 km there and back. With a petrol car averaging 6.5 l/100 km and an illustrative pump price of 18 kr a litre:

• 940 × 6.5 ÷ 100 = 61.1 litres
• 61.1 × 18 = 1,099.80 kr, so call it 1,100 kr

Check the actual price at the pump. It changes often, and a few kronor a litre adds up.

The fuel cost calculator does this sum for you, per person, with wear, tolls and parking included if you want them.

Or skip the formula: full to full

The owner fills the tank before leaving, at their own cost, since that tank was theirs anyway. Every fill-up during the trip goes into the pot, including a last one back to full just before you get home. The receipts are then exactly what the trip used, and nobody needs to know the car's consumption. Use the formula when that isn't possible: the tank was half empty when you left, or you're only splitting one part of a longer drive.

Should the owner get something for the car?

On anything longer than a day trip, yes. Fuel is only part of what a kilometre costs the owner. Tyres, servicing and the car losing value as the mileage goes up are real costs too, and the owner pays all of them. If passengers only pay for fuel, the owner is quietly subsidising everyone else's trip.

Don't try to calculate the true cost per kilometre; you'll end up with a number that feels like a taxi meter. Agree a small round figure before you leave, such as 50 öre per km, add it to the car total and split it like everything else. The owner pays their own share of it too, which is fair, since they were on the trip as well.

It goes down better if a passenger suggests it, so the owner doesn't have to ask:

You're putting 900 km on your car for this. Shall we add 50 öre a km on top of the fuel?

With a rental car there's no wear to pay for. The rental fee replaces it, and the hire, fuel and any extra-driver fee are split equally.

The whole weekend, worked out

Four friends drive from Stockholm to Göteborg in Johan's car. Johan pays for the fuel and the parking.

That's 467.50 kr each. Johan has paid 1,400 kr out of pocket, so each of the three passengers sends him 467.50 kr, or 470 if nobody minds the extra 2.50.

Notice that this is almost exactly what you'd get if the three passengers had split the 1,400 kr of fuel and parking between them and Johan had paid nothing: 466.67 kr each. In a car of four on a trip like this, "the owner rides free" and "50 öre a km" land in the same place, so use whichever is easier to explain.

They stop matching when the car is emptier. With only one passenger, "the owner rides free" would leave that passenger paying the whole 1,400 kr, while the per-km method gives 935 kr each. The fewer people in the car, the more it matters to use the per-km version.

If the car is only one part of a longer trip where several people are paying for different things, put the car total into the shared log as one line and settle everything together, as in the group holiday guide.

Electric cars

Fast-charging receipts work like fuel receipts: they go in the pot. The part people forget is the charging at the owner's home, which shows up on their electricity bill a month later. Use the same full-to-full idea. The charge the car left home with is the owner's, and whatever it takes to get the battery back to that level, on the road or at home afterwards, belongs to the trip. If topping up at home takes 50 kWh and the owner pays around 2 kr per kWh including grid fees (illustrative; it varies a lot by region and month), add 100 kr.

To estimate the whole trip instead, use the formula with electricity: 940 km at 18 kWh per 100 km is about 169 kWh, priced at whatever mix of home and public charging you used. Free chargers at the hotel are free for everyone. The per-km wear amount applies the same as for a petrol car.

Tolls, bridges, ferries and parking

These are car costs: into the pot, split between whoever was in the car. Watch for the ones that turn up later.

• Congestion tax in Stockholm and Göteborg is billed to the car's owner afterwards, so nobody sees it on the day. Add it when the bill arrives, or estimate it before you settle. Rental companies pass it on, sometimes with an admin fee.
• Norwegian road tolls are mostly automatic, and the bill can arrive weeks after you're home.
• The Øresund Bridge is paid at the toll station, so at least that one comes with a receipt.
• Trafikverket's yellow road ferries are free. On paid car ferries, such as to Gotland, the fare for the car is a car cost, while passenger tickets and cabins are personal.
• Parking fines and speed camera fines are on whoever was driving or parked the car, not the group.

Passengers who join for one leg

Split each leg between the people in the car for that leg. In the example, fuel plus wear is 1,570 kr for 940 km, or 785 kr for each 470 km leg. If a colleague of Johan's gets a lift back from Göteborg, the drive out is split four ways (196.25 kr each) and the drive home five ways (157 kr each). She pays 157 kr, everyone else's return leg gets cheaper, and the parking stays with the four who parked.

Detours to pick someone up are shared: you wanted them along, and a fuller car is cheaper per head. A detour for one person's errand on the way, such as an outlet village an hour off the E20, can go on that person if it adds more than a few dozen kilometres. Anything shorter, let it go.

The same sums work for a winter drive to the mountains, where the car is only one part of the bill. The ski trip guide shows them alongside the cabin, lift passes and the person who comes up a day late.

Camping gear and food

Borrowed gear is free; give it back clean and dry. Gear bought for the trip that one person keeps afterwards (a tent, a cool box, a stove) is theirs to pay for, even if everyone used it. Otherwise the group has just bought that person a tent. Consumables are shared: gas canisters, charcoal, firewood, bin bags. Campsites usually charge per pitch plus per person, sometimes with electricity on top, and the pitch fee is split between everyone on it.

Do one big food shop at the start and split it between everyone eating. Petrol station coffee and sweets for the drive are personal. If the shop is mostly shared food with a few personal things, subtract those and split the rest. If it's a real mix, scan the receipt in Qvitt: everyone taps their own items, and shared ones can be split into equal parts so each person claims a part. If the drive ends at a cabin, the guide to splitting a cabin weekend covers the big food shop and the Systembolaget run.