Heat pump cost as a share of gas boiler cost
Estimate of running cost only. Excludes servicing, installation and electricity standing charges, which you pay either way.
Formula and breakdown
Heat demand = gas use x boiler efficiency
Heat pump electricity = heat demand / SCOP
Costs = kWh x price
Break-even SCOP = electricity price x boiler efficiency / gas price
This heat pump running cost calculator compares the yearly cost of heating your home with a heat pump against a gas boiler, for UK households first and for Irish and European homes with their own prices. You enter your gas use or heat demand, boiler efficiency, the heat pump’s SCOP and your tariffs, and it shows the yearly saving or extra cost, plus the SCOP you need to break even.
Quick answer: A heat pump running cost calculator divides your yearly heat demand by the heat pump’s SCOP and multiplies by the electricity price. At October 2026 UK cap prices of 26.32p for electricity and 7.97p for gas, a heat pump needs a SCOP of about 3.0 to match a 90% efficient gas boiler.
What Is a Heat Pump Running Cost Calculator?
A heat pump running cost calculator is a tool that estimates how much electricity a heat pump needs to deliver the same heat your boiler provides today, and what that electricity costs compared with the gas. The formula in plain words: your gas use multiplied by boiler efficiency gives the heat your home really uses; that heat divided by the heat pump’s SCOP gives the electricity needed; each fuel is then multiplied by its price.
Starting from gas use matters. A boiler never turns all of its gas into heat, so 9,500 kWh of gas burnt at 90% efficiency delivers about 8,550 kWh of heat. That 8,550 kWh is what the heat pump has to supply, not the full 9,500.
How Do You Use the Heat Pump Running Cost Calculator?
- Choose your starting point: yearly gas use from your bill, or a heat demand figure from an EPC or heat loss survey.
- Enter the gas figure in kWh. Your annual statement shows it; the default is Ofgem’s typical domestic consumption value for gas of 9,500 kWh, used from July 2026.
- Set the boiler efficiency. Around 90% suits a modern condensing boiler; older non-condensing boilers are lower.
- Enter the heat pump SCOP from your installer’s quote or design. The default of 3.0 is an example only.
- Check the electricity and gas prices. They start at the October to December 2026 cap; replace them with your own, or with a heat pump tariff average.
- Say whether the gas supply stays connected. If it is capped off, the gas standing charge is counted as a saving.
- Read the yearly difference, the break-even SCOP and the cost per kWh of heat for each system.
How Much Does a Heat Pump Cost to Run Compared With a Gas Boiler?
At October 2026 UK cap prices, a heat pump with a SCOP of 3.0 costs almost exactly the same to run as a 90% efficient gas boiler: about £750 a year against about £757 for a home using 9,500 kWh of gas. The reason is the price gap. Under the Ofgem price cap for October to December 2026, electricity costs 26.32p per kWh and gas 7.97p per kWh, so electricity is about 3.3 times the price of gas. A heat pump has to turn each kWh of electricity into more than three kWh of heat just to keep level.
The table shows how the result moves with SCOP for that same typical home, with the gas supply kept connected.
| Heat pump SCOP | Electricity used per year | Heat pump cost per year | Gas boiler cost per year | Difference |
|---|---|---|---|---|
| 2.5 | 3,420 kWh | £900.14 | £757.15 | £142.99 more |
| 3.0 | 2,850 kWh | £750.12 | £757.15 | £7.03 less |
| 3.5 | 2,443 kWh | £642.96 | £757.15 | £114.19 less |
| 4.0 | 2,138 kWh | £562.59 | £757.15 | £194.56 less |
Based on 9,500 kWh of gas, 90% boiler efficiency, 26.32p electricity and 7.97p gas. Standing charges not included.
What SCOP Do You Need to Break Even?
The break-even SCOP equals the electricity price times the boiler efficiency, divided by the gas price, which is about 2.97 at current UK cap prices with a 90% boiler. Above that number the heat pump is cheaper to run; below it the boiler wins. The heat pump running cost calculator shows this figure live, so you can see at once how a cheaper electricity rate lowers the bar. At an average heat pump tariff of 20p per kWh, for instance, the break-even SCOP drops to about 2.26.
The Energy Saving Trust’s air source heat pump advice makes the same point: on standard tariffs heat pumps can cost slightly more to run than a new gas boiler, while a heat pump time-of-use tariff can make them cheaper.
Does Removing the Gas Supply Change the Saving?
Yes, capping off the gas supply saves the full gas standing charge, which is 29.68p a day or about £108 a year under the current cap. Many households keep gas only for a hob. If you switch to electric cooking as well, that daily charge disappears, and in the typical example above the yearly saving rises from about £7 to about £115. Choose “Capped off” in the calculator to include it. Electricity standing charges are left out because you pay them in both cases.
Worked Example: James Compares Options in Bristol
James in Bristol used 12,000 kWh of gas last year in a boiler he estimates at 88% efficiency. His installer quotes a heat pump with a design SCOP of 3.2.
- Heat demand: 12,000 x 0.88 = 10,560 kWh.
- Heat pump electricity: 10,560 / 3.2 = 3,300 kWh.
- Heat pump cost at 26.32p: 3,300 x £0.2632 = £868.56.
- Gas boiler cost at 7.97p: 12,000 x £0.0797 = £956.40.
- Saving on the standard cap: £87.84 a year.
James then tries a time-of-use tariff that he expects to average 20p per kWh for his heating. The heat pump cost falls to 3,300 x £0.20 = £660.00, a saving of £296.40. He also plans to cap off the gas, which adds £108.33, taking the yearly saving to £404.73. The 20p figure is his own estimate, which is why the calculator keeps the price fully editable.
Is There a Grant to Help With the Cost of a Heat Pump?
Yes, in England and Wales the Boiler Upgrade Scheme offers £7,500 towards an air source or ground source heat pump, £2,500 towards an air-to-air heat pump, and an extra £1,500 until March 2027 for homes currently heated by oil or LPG. Scotland and Northern Ireland run separate schemes. The grant reduces installation cost, not running cost, so use it in a payback calculation alongside the yearly saving from this page.
Pairing a heat pump with panels can cut running costs further during spring and autumn. Our solar panel savings calculator estimates how much generation you would use at home, and the home battery savings calculator tests shifting cheap overnight electricity into the day.
Why Might Real Running Costs Differ From the Estimate?
The biggest uncertainty is the SCOP your system achieves in practice, because it depends on design, weather and controls. A quoted SCOP is a design estimate; settings that differ from the design, or a colder winter than average, can lower the figure you actually get. Gas use also includes cooking and hot water, so if you keep a gas hob, subtract a little from the gas figure. Treat the heat pump running cost calculator result as a planning guide and compare it with your actual meter readings after the first year. To see how heating fits with the rest of your electricity use, try the energy consumption calculator; for portable electric heaters instead of a whole-house system, the electric heater running cost calculator is a better fit.
Frequently Asked Questions
How much does a heat pump cost to run per year in the UK?
For a home using 9,500 kWh of gas in a 90% efficient boiler, a heat pump with a SCOP of 3.0 needs about 2,850 kWh of electricity, costing about £750 a year at 26.32p per kWh. The gas boiler would cost about £757 in fuel.
What SCOP does a heat pump need to beat a gas boiler?
Divide the electricity price by the gas price and multiply by the boiler efficiency. At 26.32p and 7.97p with a 90% boiler, the break-even SCOP is about 2.97. Any SCOP above that, or a cheaper electricity rate, makes the heat pump cheaper to run.
What is SCOP on a heat pump?
SCOP stands for seasonal coefficient of performance. It is the heat delivered over a full heating season divided by the electricity used. A SCOP of 3.0 means three kWh of heat for each kWh of electricity, averaged across mild and cold weather.
Do I still pay a gas standing charge with a heat pump?
Only if your gas supply stays connected, for example for a gas hob. If the supply is capped off you stop paying it, which is 29.68p a day or about £108 a year under the October to December 2026 cap. The calculator lets you include this saving.
Is there a grant for a heat pump in the UK?
In England and Wales the Boiler Upgrade Scheme offers £7,500 towards an air source or ground source heat pump and £2,500 towards an air-to-air heat pump. Homes heated by oil or LPG can get an extra £1,500 until March 2027, according to gov.uk.
How can I lower my heat pump running costs?
Ask your installer which SCOP the design is based on and make sure the system is set up to reach it, then use a time-of-use or heat pump tariff if one suits your routine. Better insulation cuts heat demand. Test each change in the calculator by editing SCOP, price or demand.
Checked October 2026 by the Solaxyra Editorial Team. Sources: Ofgem energy price cap October to December 2026, Ofgem typical consumption values from July 2026, GOV.UK Boiler Upgrade Scheme, Energy Saving Trust air source heat pumps, Wikipedia: Condensing boiler.