What does a spa pool / hot tub cost to run?
A typical spa pool / hot tub running at its typical daily hours costs about $153/month to run in New Zealand - that's $1841/year at the current national average rate of 42.0c/kWh.
| Region | Rate | Monthly |
|---|---|---|
| Dunedin | 42.4c/kWh | $155 |
| Queenstown | 42.3c/kWh | $154 |
| Auckland Central | 41.2c/kWh | $150 |
| Christchurch | 38.5c/kWh | $141 |
| Wellington City | 37.0c/kWh | $135 |
This estimate models a typical spa pool / hot tub running at its typical daily hours. At the national average rate of 42.0c/kWh, that works out to about 365 kWh a month - $153/month, or $1841 across a year.
- Power draw
- 4,000 W
- Typical use
- 3 hrs/day, 7 days/week
- Rate applied
- 42.0c/kWh (national average)
- Energy used
- 365 kWh/month · 4,380 kWh/year
Your own usage will differ - adjust the hours, wattage and rate for your household in the full calculator.
What to know about running a spa pool / hot tub
A spa pool or hot tub is one of the most expensive appliances a home can own, and the cost is sneaky because it is not really about the time you spend in it. A spa keeps a large body of water hot 24/7, constantly topping up the heat it loses to the air, so it draws power around the clock. Through winter, when the temperature gap is biggest, it can add $100-$200 a month on its own.
Most people assume the cost comes from the times they actually soak, but that is the small part. The real bill is written the other twenty-three hours a day, when nobody is in the water and the heater is still working to hold four hundred-odd litres at a steady temperature against the cold air pressing in from outside.
That is why winter hits so hard. The colder the air around the spa, the faster the heat bleeds out and the more often the heater has to kick in to replace it, which is how a spa can quietly add $100-$200 a month at the worst of the year. The bigger the gap between the water and the air, the harder it works.
The cost is dominated by heat loss, which means the cover is everything. A well-fitting, well-insulated cover that is actually kept on between uses can halve the running cost, because most of the escaping heat leaves through the open surface of the water. Keeping a good cover shut when you are not in the spa is the single most powerful thing you can do.
Beyond that, siting the spa out of the wind helps, as does keeping the water only as hot as you actually use it, and in some cases dropping the set temperature when you are away for a stretch. Wind strips heat off the surface, every extra degree of set temperature is more heat to maintain, and a spa nobody will touch for a week does not need to stay at full soaking heat.
It is a real luxury cost, worth knowing about before the first winter bill lands. None of this means a spa is not worth having, only that it pays to run it with the cover on, out of the wind and no hotter than you need. Put your spa into the calculator to see what those winter months look like, and how much a disciplined cover habit claws back.
Frequently asked
How much does a spa pool / hot tub cost to run in NZ?
At the national average electricity rate of 42.0c/kWh, a typical spa pool / hot tub costs about $153 per month, or $1841 per year. Actual costs vary by region and how heavily you use it.
Which NZ region has the cheapest spa pool / hot tub running cost?
Of the five centres shown on this page, Wellington City is the cheapest at $135/month, and Dunedin is the most expensive at $155/month. The 30% spread reflects regional MBIE retail rates.
Any tips for reducing this cost?
A spa pool can add $100-200/month to your bill in winter
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