How much fuel your trip will cost
Before a long drive it helps to know how much fuel you’ll burn and what it will cost. This calculator answers both from three inputs: the distance, your vehicle’s efficiency, and the price per liter. Travelling with others? It also splits the total between passengers. Everything runs in your browser, and nothing you type is stored.
How the trip cost is worked out
The logic is short. First estimate the liters you need, then multiply by the price:
- Fuel needed = distance ÷ efficiency (when efficiency is in km/L).
- Total cost = liters × price per liter.
- Cost per person = total cost ÷ number of passengers.
Tick the round trip box and the distance doubles automatically, because the drive home burns just as much as the drive out.
Worked example
Picture a 300 km trip in a car that does 12 km/L, with fuel at $60 per liter:
- Fuel:
300 ÷ 12 = 25 L - Total cost:
25 × 60 = $1,500
Make it a round trip and the distance rises to 600 km, so you need 50 L and pay $3,000. Split evenly between 4 people, each one chips in 3,000 ÷ 4 = $750.
| Scenario | Distance | Fuel | Total cost | Per person (4) |
|---|---|---|---|---|
| One way | 300 km | 25 L | $1,500 | $375 |
| Round trip | 600 km | 50 L | $3,000 | $750 |
km/L vs L/100km: two ways to measure the same thing
Fuel economy is usually written in one of two units:
- km/L (kilometers per liter): how far you go on one liter. Higher is better.
- L/100km (liters per 100 km): how much you burn over 100 km. Lower is better.
They are inverses of each other. To switch between them, divide 100 by the value:
- From km/L to L/100km:
100 ÷ 12 = 8.33 L/100km - From L/100km to km/L:
100 ÷ 8.33 = 12 km/L
The calculator takes either unit through a selector, so use whatever appears on your spec sheet or dashboard without converting by hand.
Tips to burn less fuel
Small habits close the gap between real and factory economy:
- Hold a steady speed and avoid hard acceleration and braking; aggressive driving can raise consumption 15-30%.
- Check your tire pressure: soft tires add rolling resistance and waste fuel.
- Drop dead weight from the trunk and remove roof racks when you aren’t using them, since they add drag.
- Use air conditioning wisely in town and switch the engine off during long waits.
- Keep up with maintenance: clogged air filters and worn spark plugs hurt efficiency.
Splitting the cost between passengers
Carpooling is the fastest way to make a trip cheaper. Enter the number of people and the calculator divides the total evenly. That’s fair when everyone rides the whole way; if someone gets off early, the usual move is to prorate by the distance each person actually travelled.
Frequently asked questions
How do I find my car’s fuel efficiency?
Check the manufacturer’s spec, or measure it yourself: fill the tank, note the odometer, drive normally, then fill up again. Divide the kilometers driven by the liters you added and you get your real km/L, which is usually a bit worse than the brochure figure.
How do I convert km/L to L/100km?
Divide 100 by your km/L figure. For example, 100 ÷ 15 = 6.67 L/100km. The same operation works in reverse: 100 ÷ 6.67 = 15 km/L.
How do we split fuel between friends?
The simplest way is an even split: total cost divided by the number of passengers. If someone only rides part of the route, calculate their leg separately and add it on. This tool shows the cost per person instantly, so no one argues over the tab.
Does the result include tolls or wear?
No. The calculator estimates fuel only. Tolls, oil, tires and general wear all add to the true cost per kilometer, but they are figured separately.