Power Bill Estimator NZ
This calculator estimates your electricity bill from how much power you use, the price you pay per unit, and your plan's daily fixed charge, so you can see what a bill is likely to be before it lands. Power bills in New Zealand have two parts, and understanding both is the key to managing them. The variable charge is what you pay for the energy you actually use, measured in kilowatt hours and multiplied by your unit price in cents. The fixed daily charge is a set amount you pay every day just to be connected, regardless of how much you use, which is why a low-user plan with a small daily charge can suit a modest household while a standard plan can be cheaper for a heavy user. This tool brings both together. You enter your average daily usage in kilowatt hours, which you can read from a past bill or your provider's app, your unit price in cents per kilowatt hour, your daily fixed charge in cents, and the number of days in the billing period. The calculator returns the estimated bill, broken into the variable energy cost and the fixed charge, and projects the figure out to a full year so you can budget ahead. The results update as you type, so you can test how cutting usage or switching to a cheaper unit rate would change the bill. Use it to sanity-check a bill, to compare plans, or to set a realistic power budget. Prices usually include GST. This is an estimate to guide you, not an exact invoice.
Bill = usage x days x unit price + daily fixed charge x days. Prices usually include GST. An estimate to guide budgeting, not an exact invoice.
How it works
The variable energy cost is your daily usage in kilowatt hours, multiplied by the number of days in the period, multiplied by the unit price converted from cents to dollars. The fixed cost is the daily fixed charge, in dollars, times the number of days. Adding the two gives the estimated bill, and scaling by 365 over the period length gives the annual figure.
Worked example
Using 18 kilowatt hours a day at 28 cents, over 30 days, the energy cost is 18 times 30 times 0.28, which is $151.20. A fixed charge of 140 cents a day over 30 days adds $42.00. The estimated bill is $193.20, which projected across a year is about $2,351.
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