How fuel cost is calculated
Total distance is multiplied by litres per 100 km and divided by 100 to estimate litres required. The litres are then multiplied by your entered petrol or diesel price.
New Zealand · Petrol and diesel
Fuel cost calculator NZ
Estimate petrol or diesel cost for a New Zealand road trip, commute or repeated journey using your distance, pump price and vehicle fuel economy.
Last reviewed: 22 August 2026
Estimated total fuel cost
$42.00
for 200 km of travel
Fuel required
15 L
Cost per kilometre
$0.210
- Cost per trip
- $42.00
- Cost per person
- $42.00
- Economy used
- 7.5 L/100 km
- Pump price
- $2.80 / L
Change the pump price or fuel economy to compare a cautious scenario with your usual trip.
Estimate only: Real fuel use changes with traffic, route, weather, load, tyres and driving style. Use your recent measured consumption where possible.
One-way and return trip costs
Enter the distance for one direction. Select return journey when you will drive back, then enter how many times that complete journey will occur.
Using L/100 km or km/L
New Zealand vehicle data commonly reports litres per 100 km. If your vehicle reports kilometres per litre, the calculator converts it using 100 divided by km/L.
Splitting petrol money
The per-person result divides the total estimated fuel cost equally by the number of people entered. It does not split parking, tolls, RUC or other vehicle costs.
Choosing a realistic fuel-consumption figure
A vehicle label or manufacturer figure is a useful starting point, but your own average can better reflect local conditions. Compare fuel added with kilometres travelled over several normal journeys. Urban traffic in Auckland, Wellington or Christchurch can produce a different result from steady open-road driving between towns.
NZTA records combined, urban and open-road fuel-consumption values in litres per 100 km. Driving smoothly, keeping tyres correctly inflated and avoiding unnecessary load can reduce fuel use, but no calculator can predict an exact fill-up.
Worked fuel-cost example
A 300 km one-way journey in a vehicle using 7.5 L/100 km requires about 22.5 litres. At $2.80 per litre, the estimated fuel cost is $63. A return journey under the same assumptions is 600 km, 45 litres and $126.
New Zealand fuel-economy sources
Use official vehicle information and your current local pump price rather than treating the example defaults as today's market price.
Frequently asked questions
How do I calculate fuel cost for a trip?
Multiply the total distance by the vehicle’s litres per 100 km, divide by 100, then multiply the litres required by the pump price per litre.
Where can I find my car’s fuel economy?
Check the vehicle fuel-economy label, owner manual or trip computer. For a more realistic estimate, calculate litres filled divided by kilometres travelled across several normal trips.
Can I use kilometres per litre instead?
Yes. Select kilometres per litre and enter the distance your vehicle travels on one litre. The calculator converts it to litres per 100 km before calculating fuel use.
Does this include a return journey?
Select return trip and the calculator doubles the entered one-way distance before applying the number of trips.
Does the result include RUC?
No. Fuel cost is separate from road user charges. Diesel vehicles and other RUC vehicles should calculate applicable RUC separately.
Why might my real fuel cost be higher?
Traffic, short cold-engine trips, hills, speed, weather, tyre pressure, air conditioning, towing and vehicle load can all change real-world fuel consumption.