New Zealand power cost calculators
There is no single New Zealand electricity price. Retail rates vary by retailer, plan and region, and a calculator that hardcodes a national average will be wrong for most of the people using it. So this one asks for the rate on your own bill.
5 calculators in this section
Power cost
What an appliance costs to run, at the rate on your own bill.
Open calculatorFirewood
Firewood for a season, in kg and cubic metres.
Open calculatorHeat pump size
A rule-of-thumb heat pump size for a room.
Open calculatorFuel cost
Trip fuel cost from distance, consumption and price.
Open calculatorCar cost
What a car really costs per year, week and kilometre.
Open calculatorQuestions these calculators answer
How do you work out what an appliance costs to run?
Multiply the wattage by the hours used, divide by 1,000 to get kilowatt hours, then multiply by your price per kilowatt hour. A 1,500 watt heater running 5 hours a day uses 7.5 kWh, which at 30 cents costs $2.25 a day — about $68 a month if it runs every day.
How much firewood do I need for a winter in NZ?
Multiply burns a week by the weeks in your season by the kilograms of wood in each burn. Burning 5 nights a week for 22 weeks at 12 kg a burn is 1,320 kg, about 3.2 loose cubic metres of dry wood with a 10% allowance. Loose and stacked measures differ, so ask what the supplier is selling.
What size heat pump do I need?
A common rule of thumb is about 0.08 to 0.12 kW of heating output per square metre of living space, depending on how well insulated the room is. A 30 m² living room at 0.10 kW per square metre needs about 3.0 kW, so a 3.5 to 4 kW unit would usually be chosen. Installers size from a detailed heat-loss assessment.
How do I calculate the fuel cost of a trip?
Multiply the distance by the fuel use per 100 km, divide by 100 for litres, then multiply by the price. A 450 km trip at 8.5 L/100 km needs 38.2 litres, which at $2.70 a litre costs $103.28. That is $0.230 per kilometre, or $25.82 each for 4 people.
How much does it cost to run a car?
Add depreciation to the running costs. A $32,000 car kept 5 years and sold for $16,000 loses $3,200 a year; with fuel of $2,592 and the other costs entered, the car costs about $8,212 a year, $157.92 a week and $0.68 a kilometre. The figures here are examples to replace with your own.
Finding your actual rate
The number you want is the variable charge per kilowatt hour on your power bill, usually shown in cents. It is not the daily fixed charge, which you pay whether or not the appliance runs, and it is not the total divided by units used, which folds the fixed charge back in and overstates the marginal cost of running something for another hour.
If you are on a plan with off-peak or night rates, run the calculation twice — the gap between the two is usually the entire argument for shifting a load.
Other NZ sections
Heating decisions often lead to the construction tools.