Cost to Heat a Pool in Australia: Per Degree, Day and Month

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Heating a 50,000 litre pool costs about $3.02–$4.87 per 1°C with a heat pump at 2026–27 regulated electricity prices (Melbourne's CitiPower zone to Adelaide), and $12.49 per 1°C with gas at Perth's regulated rate. If the pool loses 2°C a night uncovered, a heat pump costs $181–$292 a month; a cover can cut that to $45–$73.

The short answer

The sum: a 50,000 litre pool needs 58.1 kWh of heat per 1°C. A heat pump at a coefficient of performance of 5 buys that with 11.6 kWh of electricity; a gas heater at 80% burns 261.5 MJ.
Heat pump, per 1°C: $3.02 in Melbourne's CitiPower zone, $3.25 in Brisbane, $3.85 in Sydney, $3.87 in Perth and $4.87 in Adelaide, at the 2026–27 regulated flat rates.
Per month, holding temperature: $181–$292 if the pool loses 2°C every night, the figure one heat pump maker sizes for. With a bubble cover cutting losses by 75%, the most energy.gov.au claims, $45–$73.
Gas: $12.49 per 1°C at Perth's regulated 17.20c a unit, about $750 a month uncovered on the same 2°C-a-night assumption, or $187 covered. Gas would have to cost under about 1.5c a megajoule to match a heat pump at Sydney's rate.
The biggest levers are the cover, then the tariff band. A heat pump running in Energex's cheapest time-of-use band, 6.9848c, costs about $0.81 per 1°C.

Cost to heat a 50,000 litre pool by city: heat pump (coefficient of performance 5) at each network's 2026–27 regulated flat rate, and a gas heater (80% efficient) at Perth's regulated gas rate. The 2°C nightly loss is one maker's sizing figure; the covered column applies energy.gov.au's best-case 75% cut (read 10 October 2026; rates include GST where the regulator states it)
City and network	Regulated rate, 2026–27	Per 1°C	Per night if it loses 2°C	30 nights, uncovered	30 nights, covered (75% less loss)
Sydney (Ausgrid network)	33.1372c per kWh	$3.85	$7.70	$231	$58
Western Sydney (Endeavour Energy network)	33.7273c per kWh	$3.92	$7.84	$235	$59
Brisbane and south-east Queensland (Energex network)	27.9744c per kWh	$3.25	$6.50	$195	$49
Adelaide (SA Power Networks)	41.9103c per kWh	$4.87	$9.74	$292	$73
Melbourne inner (CitiPower zone)	25.96c per kWh	$3.02	$6.03	$181	$45
Melbourne south-east (United Energy zone)	27.35c per kWh	$3.18	$6.36	$191	$48
Melbourne outer east (AusNet Services zone)	31.98c per kWh	$3.72	$7.43	$223	$56
Perth (Synergy Home Plan A1)	33.2621c per kWh	$3.87	$7.73	$232	$58
Perth, gas heater (Mid-West/South-West gas area)	17.20c per unit (1 unit = 3.6 MJ)	$12.49	$24.99	$750	$187

How much does it cost to heat a pool per day? The worked calculation

Heating cost is three numbers multiplied together, and you can do it with your own bill:

Heat per degree. Water takes 4,184 joules per kilogram to warm by 1°C, the figure the USGS publishes. A 50,000 litre pool therefore needs 58.1 kWh of heat for each 1°C. The derivation and the time it takes are on how long a pool takes to heat up; scale it to your volume (a 30,000 litre pool needs 34.9 kWh).
What the heater burns to deliver it. A heat pump moves heat from the air. One maker's brochure lists coefficients of performance at full output of about 4.2–5.2 with 15°C air across three ranges, and about 6.2–7.4 with 27°C air. At 5, the 58.1 kWh costs 11.6 kWh of electricity. A gas heater burns fuel: one maker's residential range turns 196 MJ an hour into 44 kW of heat, about 81%, so at 80% the same 58.1 kWh takes 72.6 kWh, or 261.5 MJ, of gas.
Your price. Multiply by the c/kWh or c/MJ on your bill.

Worked for Sydney on Ausgrid's 2026–27 default market offer of 33.1372c/kWh: 11.6 kWh × 33.14c = $3.85 per 1°C. A first warm-up of 8°C costs about $30.81 before losses. On a warm day the same unit at a coefficient of performance near 7 needs 8.3 kWh per degree, $2.75.

Per day, the question is how much heat the pool loses overnight, because that is what the heater buys back. One heat pump maker sizes its units on the basis that night-time loss can reach 2°C. At that rate a Sydney heat pump costs about $7.70 a day to hold temperature, and the table shows every city.

The quotable version: heating a 50,000 litre pool costs 11.6 kWh of electricity per degree with a heat pump, so your c/kWh × 11.6 is your cost per degree.

Pool heat pump cost to run per month, by city

The table uses the regulated flat rate for each network, read at the regulators on 10 October 2026. In NSW, south-east Queensland and South Australia that is the Australian Energy Regulator's 2026–27 default market offer (Ausgrid 33.1372c, Endeavour 33.7273c, Energex 27.9744c, SA Power Networks 41.9103c, all including GST). In Victoria it is the Essential Services Commission's Victorian Default Offer (CitiPower 25.96c, United Energy 27.35c, Jemena 27.47c, AusNet Services 31.98c, including GST). In Perth it is Synergy's A1 Home Plan at 33.2621c. These are the standing prices; a market offer may be cheaper, so substitute your own rate.

On a 2°C-a-night loss, 30 nights of heat pump heating costs $181 in Melbourne's CitiPower zone, $195 in Brisbane, $231 in Sydney, $232 in Perth and $292 in Adelaide. Those are ceilings for a cool-season month on that assumption, not averages: on warm nights the pool loses less and the heat pump runs at a better coefficient of performance.

The tariff band matters as much as the city. The AER's 2026–27 time-of-use cap for Energex includes a band at 6.9848c/kWh; a heat pump running inside it costs about $0.81 per 1°C instead of $3.25. Check which hours your own time-of-use bands cover before you set the heater timer. Outside NSW, the building code already requires a time switch on a gas or heat pump pool heater; whether you need a timer on your pool heater covers the rule.

Running cost is separate from buying the unit: what a pool heater costs installed covers purchase, and what size heat pump you need covers sizing.

The quotable version: at 2026–27 regulated prices, a heat pump holding a 50,000 litre pool against a 2°C nightly loss costs $181–$292 a month, depending on the network.

Is gas or a heat pump cheaper to run on my bill? The 1.5 cent rule

The default market offer and the Victorian Default Offer cover electricity only. The one regulated household gas price we found is Western Australia's: the 2026–27 maximum in the Mid-West/South-West area, which includes Perth, is 19.06c a unit for the first 12 units a day and 17.20c beyond that, where a unit is 3.6 MJ. A pool heater runs well past 12 units a day, so the 17.20c rate applies: 72.6 units × 17.20c = $12.49 per 1°C, about three times a heat pump at Synergy's A1 rate ($3.87).

Elsewhere, gas is priced by your retailer in cents per megajoule. Use the same sum: 261.5 MJ × your c/MJ = your cost per degree with an 80% efficient heater. Then compare it with a heat pump on your electricity rate.

The 1.5 cent rule: at Ausgrid's 33.14c/kWh, gas has to cost less than about 1.47c a megajoule before a gas heater is cheaper per degree than a heat pump running at a coefficient of performance of 5. Perth's regulated rate works out at 4.78c a megajoule. Gas still has a place: it heats fast and does not care about air temperature, which suits occasional weekend heating; solar vs gas vs heat pump pool heating compares the three by how you use the pool.

Solar is not in the table because it has no fuel cost: you pay only for the pump that pushes water through the collectors, and that depends on your pump and plumbing.

How much does a pool cover cut my heating cost?

energy.gov.au says bubble covers can cut heat losses from a heated pool by as much as 75%. Applied to the 2°C-a-night loss, that is 0.5°C a night, and the monthly heat pump bill falls from $181–$292 to $45–$73; Perth's gas bill from $750 to $187. Treat the covered column as a best case: 75% is the top of energy.gov.au's range, and a cover only works while it is on the water.

Outside NSW, a pool heated by gas or a heat pump must have a cover under the building code's housing provisions, so for most owners the covered column is the relevant one. What the cover costs and how fast it pays back is on pool cover cost and payback.

If you are pricing heating into a new pool, ask each builder to state the heater's output, its coefficient of performance at 15°C air, and the cover, then compare pool quotes on the same specification. Listed businesses cover Sydney, Brisbane, Melbourne and Perth.

The quotable version: a cover that cuts heat loss by 75% cuts the heating bill by the same share, because the heater only buys back what the pool loses.

Common questions

How much does it cost to heat a pool in Australia?

For a 50,000 litre pool, about $3.02–$4.87 per 1°C with a heat pump at 2026–27 regulated electricity prices, and $12.49 per 1°C with gas at Perth's regulated rate. Monthly cost depends on how much heat the pool loses: $181–$292 for a heat pump at 2°C a night uncovered.

How much does a pool heat pump cost to run per month?

At a 2°C nightly loss, $181 in Melbourne's CitiPower zone to $292 in Adelaide for a 50,000 litre pool, using the AER's 2026–27 default market offer and the Victorian Default Offer. With a cover cutting losses by 75%, $45–$73.

How much does it cost to heat a pool per day?

About $6.03–$9.74 a day with a heat pump if a 50,000 litre pool loses 2°C overnight, depending on the network's regulated rate; $7.70 in Sydney. With gas at Perth's regulated rate, about $24.99.

Is a heat pump cheaper than gas to heat a pool?

Usually, per degree. A heat pump at a coefficient of performance of 5 uses 11.6 kWh per 1°C on a 50,000 litre pool; an 80% gas heater burns 261.5 MJ. At Sydney's 33.14c/kWh, gas would need to cost under about 1.47c a megajoule to match.

Does a pool cover reduce heating costs?

Yes. energy.gov.au says bubble covers can cut heat losses from a heated pool by as much as 75%, and the heating bill falls in proportion. Outside NSW, gas and heat pump heated pools must have a cover under the building code.

Sources

General information only, current at 2026-10-10. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.