--- title: "Fuel Cost Calculator for New Zealand: Cars and EVs per Trip | AumnI tools" description: "Cost a New Zealand drive in kilometres using the MBIE board price per litre and L/100 km, compare petrol cars with an EV, split by passengers and see the CO₂." url: https://aumnitools.com/nz/tool/fuel-cost-calculator category: "Lifestyle" country: "New Zealand" updated: 2026-11-08 --- # Fuel Cost Calculator Planning a drive from Auckland to Wellington means asking what the litres will cost and who chips in. This version opens in kilometres and L/100 km, fills the price box with the latest MBIE weekly board price for 91 petrol, and prices one trip across every vehicle you add. ## New Zealand rules and figures - New Zealand sells fuel by the litre, and everyday distances are in kilometres with economy in litres per 100 km. - MBIE’s weekly fuel price monitoring gave a provisional Regular 91 petrol board price of 3.57 per litre on 30 October 2026. - EECA runs the national vehicle fuel economy label, which is where litres per 100 km figures for new cars are published. - GST of 15% is included in New Zealand shelf prices, so type the price displayed at the pump without adding tax. Sources: [MBIE: Weekly fuel price monitoring](https://www.mbie.govt.nz/building-and-energy/energy-and-natural-resources/energy-statistics-and-modelling/energy-statistics/weekly-fuel-price-monitoring) (checked 2026-11-08); [EECA: Vehicle fuel economy label](https://www.eeca.govt.nz/regulations/vehicle-emissions-and-energy-economy-labelling-programme/about-the-vehicle-emissions-and-energy-economy-labelling-programme/) (checked 2026-11-08) ## How the fuel cost calculator works Fuel use is held as litres per 100 km, so distance and the two adjustment factors multiply it directly. The result is multiplied by the price per litre, which starts at the MBIE board price and can be replaced for each car. Formula: `litres = L/100 km × style × conditions × km ÷ 100; cost = litres × board or pump price` - The starting trip is 500 km for 2 people. Our car uses 7.5 L/100 km, The big one 11.5, and both start at 3.57 per litre, the provisional MBIE Regular 91 board price for 30 October 2026. - A board price is a reference figure rather than what a forecourt displays, so type your own price if you know it. - For the EV row, 17 kWh per 100 km and a placeholder 0.30 per kWh are assumed; change both to match your power plan. - Return trip doubles the distance, and trips per year multiplies the gap between the cheapest and dearest vehicle. ## How to use the fuel cost calculator 1. **Keep the metric units.** New Zealand starts in kilometres, litres and L/100 km. The Units box can change them if a vehicle’s figures come in mpg. 2. **Describe the drive.** Enter the distance and People in the car. Switch to Return trip for a loop that ends where it started. 3. **Review the price.** Open Compare vehicles. Each petrol car begins at the 91 board price; overwrite it with the pump price you saw. 4. **Choose road conditions.** Pick a driving style and a condition such as cold weather or hills for roads like the Desert Road in winter. 5. **Read what you save.** Check the cheapest vehicle, then use Trips like this per year to see a yearly difference in dollars and CO₂. ## Example: 500 km at the 91 board price of 3.57 a litre For 500 km, Our car at 7.5 L/100 km burns 37.5 litres. At the MBIE Regular 91 board price of 3.57 on 30 October 2026 (provisional), that is $133.88, or $66.94 a head with 2 aboard, and 86.6 kg of CO₂. The big one at 11.5 L/100 km costs $205.27. An electric car at 17 kWh per 100 km draws 85.0 kWh and costs $25.50 at 0.30. It undercuts the big one by $179.77. ## When to use the fuel cost calculator - **Auckland to Wellington.** Enter the distance for the one-way drive and see the cost per person for a car-load of four before agreeing on a petrol kitty. - **Choosing a rental.** Add each hire car at its L/100 km and compare petrol cost for the same South Island loop. - **Plug-in versus petrol commute.** Add an Electric vehicle with your power plan’s rate and set trips per year to see the difference over a year of commuting. - **Cold-weather planning.** Switch conditions to cold weather to see the extra litres a winter pass crossing adds. ## What the fuel cost calculator does not do - The style and condition factors are rough multipliers applied equally to every vehicle. They are not measurements of your car. - Costs cover fuel or electricity only: no tolls, parking, wear, depreciation or charging losses beyond the consumption you enter. - Each vehicle has one fuel price and the CO₂ figures are tailpipe estimates from fixed constants, with a single grid intensity for all electric vehicles. - The cost split between passengers is always equal, and hybrids and plug-ins are not modelled. - Settings are not saved; reloading restores the three starting vehicles. The built-in pump price is a national average from an official page on the date shown, not the price at your station, and some countries have no single published average, in which case you enter it. ## When something else is a better fit - **When you do not know the distance yet and need a straight-line or road estimate**, use the [Distance Calculator](https://aumnitools.com/tool/distance-calculator.md). - **When you want fuel as one line in a whole trip budget**, use the [Trip Planner](https://aumnitools.com/tool/trip-planner.md). - **When you need real consumption for a particular route and load**, use your car's trip computer or a full-tank fill-up record. ## Questions about the fuel cost calculator ### Where does the 3.57 price come from? It is the provisional Regular 91 petrol board price in MBIE’s weekly fuel price monitoring for 30 October 2026. It is a reference figure, so replace it with your forecourt price for an accurate total. ### What does 500 km cost in a 7.5 L/100 km car? 37.5 litres, which is $133.88 at 3.57 a litre. Two people sharing pay $66.94 each. A hilly route lifts the litres by 15% through the Conditions box. ### Will the price update by itself? No. The built-in figure is fixed to the date shown on the page, and board prices move every week. Type a newer price into a vehicle to override it. ### Is diesel priced differently? Only if you type a different figure. Set Fuel to diesel for the CO₂ factor of 2.68 kg per litre, and enter that car’s diesel price in its own box because the starting price is for 91 petrol. ### How do I compare with an electric hatchback? Switch a vehicle to Electric and enter its kWh per 100 km and your tariff. The default 17 kWh and 0.30 give $25.50 for 500 km, against $133.88 for the 7.5 L/100 km car. ## Related tools - [Distance Calculator](https://aumnitools.com/tool/distance-calculator.md): Great-circle distance, bearings and midpoint between two points or 32 cities - [Trip Planner](https://aumnitools.com/tool/trip-planner.md): Trip itinerary, budget per person and packing list, saved in your browser - [Unit Converter](https://aumnitools.com/tool/unit-converter.md): Converts 102 units in 11 categories, with temperature offsets and 0 to 12 decimals ## About this page Runs in your browser: what you enter is processed on this device and is not uploaded. Last checked against the tool's code on 2026-11-08. Interactive version: https://aumnitools.com/nz/tool/fuel-cost-calculator