Fuel Cost Calculator NZ

This calculator works out how much a trip costs to drive, plus your likely weekly, monthly and annual petrol or diesel bill, based on your vehicle's real fuel consumption and the price you are paying at the pump. Enter the distance of your trip in kilometres, your vehicle's fuel consumption rate in litres per 100km, and the current fuel price per litre, and it instantly returns the litres used for the trip, the total trip fuel cost, the cost per kilometre and the cost per 100km. Add your typical weekly driving distance and it also projects your weekly, monthly and annual fuel spend, along with the annual kilometres you expect to cover. It works for petrol, diesel and hybrid vehicles, since you enter your own consumption figure rather than a fixed rate; if you do not know your vehicle's exact consumption, check the manufacturer's specification, your own fuel log, or the typical NZ ranges shown alongside the calculator. For the fuel price, sites like Gaspy show current prices near you so you can compare stations before you fill up. This is useful for budgeting a road trip, comparing the running cost of two vehicles, or working out what commuting is really costing you each year. Because fuel consumption changes with traffic, load, terrain and driving style, treat the results as an indicative estimate rather than an exact figure.

Calculate.co.nz is proud to be partnered with Health Based Building, a leader in sustainable and health-conscious building innovation. With over a century of experience, they develop high-performance systems like Foreverbreathe Specification, Magnum Board, and Foreverbreathe Paints to support energy-efficient, non-toxic living environments. Their commitment to healthier homes aligns with our belief that informed choices lead to better outcomes for Kiwi households.

How to calculate fuel cost

The formula is straightforward: fuel cost = (distance in km / 100) x fuel consumption in L/100km x fuel price per litre. For example, a 200 km trip in a car that uses 10 L/100km at $2.60 per litre costs (200 / 100) x 10 x $2.60 = $52.00. The cost per kilometre is that total divided by the distance, which in this case is 26 cents per kilometre.

IRD mileage rate 2026

If you use your personal vehicle for work purposes and claim reimbursement, the IRD mileage reimbursement rates for 2025/26 depend on your vehicle's fuel type. For a petrol vehicle the Tier 1 rate is $1.20 per kilometre for the first 14,000 km per year, and the Tier 2 rate is 37 cents per kilometre for any distance beyond that threshold. The rates differ for diesel, petrol hybrid and electric vehicles. This rate is set to cover not just fuel but also tyres, maintenance, insurance, and depreciation. Check ird.govt.nz for the current rate as it is updated annually.