Updated 25 September 2026 with Ofgem October to December 2026 rates

Heat pump running cost calculator

What a heat pump would cost to run in your home, a year and a month, against the heating you have now. A typical 3 bed semi costs about £705 a year, £59 a month, on a heat pump tariff, against £877 with a gas boiler.

Your home

Five questions give the running cost. The last two are optional and make it more precise.

Heat pump tariffs such as Cosy Octopus charge less in set hours; 19.8p is what a heat pump pays on average with most heating in the cheap hours. Compare tariffs.

From your annual statement. Leave it blank and we use the median for homes like yours.

Leave this on typical unless an installer has given you a seasonal efficiency (SCOP) for your design.

What it would cost to run

Heat pump, a month
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Averaged over the year
Heat pump, a year
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Your heating now
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Difference a year
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Running costs cover heating and hot water, before standing charges. Priced at the Ofgem price cap for October to December 2026: electricity 26.32p and gas 7.97p per kWh. Heating oil is 11.3p per kWh, the BoilerJuice UK average on 25 September 2026, and LPG 9.5p, our assumption. How we work it out.

Heat pump running costs by home

What a heat pump costs to run each year for heating and hot water, against a gas boiler, in homes with average insulation. The heat pump runs at 2.78, the median whole system efficiency measured in real homes. Standing charges are not included.

HomeHeat needed (kWh)Gas boilerHeat pump, standard rateHeat pump, heat pump tariffTariff, a month
2 bed flat6,390£566£605£455£38
2 bed mid-terrace6,300£558£596£449£37
2 bed bungalow8,280£733£784£590£49
3 bed mid-terrace8,820£781£835£628£52
3 bed semi9,900£877£937£705£59
3 bed detached10,530£932£997£750£62
4 bed detached13,140£1,164£1,244£936£78
5 bed detached17,550£1,554£1,662£1,250£104

On the standard rate a heat pump costs about 7% more to run than a gas boiler. On a heat pump tariff it costs about 20% less. Our heat pump running costs guide explains the maths in full.

The electricity price where a heat pump wins

A heat pump is cheaper to run than your boiler when electricity costs less than the boiler's cost per kWh of heat multiplied by the heat pump's efficiency. Below these prices the heat pump wins; above them the boiler does.

ReplacingEfficiency 2.55Efficiency 2.78 (median)Efficiency 3.05Efficiency 3.25
Gas boiler22.6p24.6p27.0p28.8p
Oil boiler33.9p37.0p40.5p43.2p
LPG boiler28.5p31.1p34.1p36.3p

The standard rate of 26.32p sits just above the gas break-even at median efficiency, which is why the tariff matters so much against gas. Against oil and LPG a heat pump is cheaper to run on any tariff under the price cap. Electric heating, whether storage heaters or panel heaters, turns 1 kWh of electricity into 1 kWh of heat, so a heat pump, using about a third as much electricity for the same heat, costs far less to run on the same tariff. Our storage heaters guide compares Economy 7 properly.

How insulation changes the running cost

Better insulation lowers the heat a home needs, and lets the heat pump run cooler and more efficiently. For a 3 bed semi on a heat pump tariff: poor insulation £853 a year, average £705, good £546 and excellent £374. With good insulation a heat pump costs less to run than gas even on the standard rate: £726 against £745. The insulation calculator shows which measures your home still needs.

How we work it out

Heat needed. The median gas used by homes of your type, size and insulation, from meter readings for 39,502 gas heated homes in the government's National Energy Efficiency Data-Framework, multiplied by 90% boiler efficiency. It includes hot water. If you enter your own gas, oil, LPG or electricity use, we use that instead: oil and LPG boilers are taken as 85% efficient, and oil is converted at 10.294 kWh a litre.

Heat pump efficiency. The whole system efficiency measured in 428 air source heat pumps by the Electrification of Heat trial, which counts hot water, the backup heater and the pumps: 2.55 for poor insulation, 2.78 for average, 3.05 for good and 3.25 for excellent. A heat pump's own SCOP on a data sheet is usually higher.

Prices. Electricity and gas at the Ofgem price cap for October to December 2026, paying by direct debit. The heat pump tariff figure of 19.8p is Cosy Octopus at October 2026 rates with 60% of heating in its cheap hours and 10% in the 4pm to 7pm peak, as costed in our tariff guide.

Frequently asked questions

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

For a typical 3 bed semi with average insulation, about £59 a month averaged over the year on a heat pump tariff at about 19.8p per kWh, or £78 a month on the standard price cap rate of 26.32p. Winter months cost several times more than summer ones, when the heat pump only makes hot water.

Is a heat pump cheaper to run than a gas boiler?

On a heat pump tariff, yes: about £705 a year for a 3 bed semi against £877 with a gas boiler, before standing charges. On the standard electricity rate it costs about £60 a year more. At the measured median efficiency a heat pump beats gas at any electricity price below about 24.6p per kWh.

Why is my installer's running cost lower than yours?

Installers usually quote the seasonal efficiency (SCOP) of the heat pump itself, often 3.5 to 4. We use 2.78, the median measured across 428 real homes in the government's Electrification of Heat trial for the whole system, including hot water, backup heating and pumps, which is what the meter records. A well designed system can beat it; choose your installer's figure in the calculator to see the difference.

Does a heat pump get rid of the gas standing charge?

Only if you have the gas supply capped, which most people do once the boiler is gone and nothing else uses gas. That saves the gas standing charge of 29.68p a day, £108.33 a year at the October to December 2026 price cap, on top of any running cost saving.

Data sources