Show the formula and working
This heat pump running cost calculator works out what an air source or ground source heat pump will cost to run for a year and compares it with a gas boiler, for homes in the UK and Europe. Enter your yearly heat demand, the heat pump’s SCOP, your electricity and gas prices, the boiler’s efficiency and the gas standing charge you would save, and it shows both costs, the difference and the SCOP you need to break even.
Quick answer: a heat pump running cost calculator divides yearly heat demand by the SCOP and multiplies by your electricity rate. For 9,000 kWh of heat at SCOP 3 and the October 2026 cap rate of 26.32p, a heat pump costs £789.60 a year, £162.61 less than an 85% efficient gas boiler.
What Is a Heat Pump Running Cost Calculator?
A heat pump running cost calculator is a tool that estimates the yearly electricity cost of heating a home with a heat pump and compares it with the cost of the same heat from a gas boiler.
The formula in plain words: electricity used equals yearly heat demand divided by the SCOP (seasonal coefficient of performance). Multiply that by your electricity unit rate for the heat pump cost. For gas, divide the same heat demand by the boiler efficiency to get the gas burned, multiply by the gas unit rate and add a year of gas standing charges. The difference is your saving or extra cost. The break even SCOP is the SCOP at which both cost the same.
How Do You Use the Heat Pump Running Cost Calculator?
- Enter your yearly heat demand in kWh for heating and hot water. Take your yearly gas kWh from your bills and multiply by your boiler efficiency (0.85 for 85%).
- Enter the heat pump SCOP from the installer’s design or the product data. 3 is the default.
- Enter your electricity unit rate. The default is the Ofgem cap of 26.32p; use your heat pump tariff if you have one.
- Enter your gas unit rate in the heat pump running cost calculator (7.97p by default) and your current boiler’s efficiency.
- Enter the gas standing charge you would save. Set it to 0 if you will keep gas for cooking.
- Read the heat pump running cost calculator results: the yearly heat pump cost, whether it is cheaper or dearer than gas, the gas boiler cost and the break even SCOP.
How Much Does a Heat Pump Cost to Run per Year in the UK?
At the October to December 2026 price cap, a heat pump with a SCOP of 3 costs £789.60 a year to supply 9,000 kWh of heat, compared with £952.21 for an 85% efficient gas boiler including the gas standing charge. That is the default result of the heat pump running cost calculator.
The heat pump running cost calculator result scales directly with heat demand: a home that needs twice as much heat pays twice as much. Ofgem’s typical medium gas use is now 9,500 kWh a year, which at 85% efficiency is about 8,075 kWh of heat. The Energy Saving Trust’s air source heat pump guide notes that on standard electricity tariffs heat pumps can cost slightly more to run than a new gas boiler, and that a heat pump time of use tariff can cut costs significantly.
What SCOP Do You Need to Beat a Gas Boiler?
At October 2026 cap prices, a heat pump beats an 85% efficient gas boiler once its SCOP is above about 2.5 if you remove gas completely, or about 2.8 if you keep gas and its standing charge for cooking.
The heat pump running cost calculator shows this as the break even SCOP. It rises if electricity gets dearer or gas cheaper, and falls on a cheaper heat pump tariff. Well designed systems with low flow temperatures and correctly sized radiators reach higher SCOPs, so ask your installer for the design SCOP and enter that figure.
| SCOP | Electricity used | Heat pump cost a year | Saving vs gas |
|---|---|---|---|
| 2.5 | 3,600 kWh | £947.52 | £4.69 |
| 3 | 3,000 kWh | £789.60 | £162.61 |
| 3.5 | 2,571 kWh | £676.80 | £275.41 |
| 4 | 2,250 kWh | £592.20 | £360.01 |
| 4.5 | 2,000 kWh | £526.40 | £425.81 |
Does a Heat Pump Tariff Make a Big Difference?
Yes: the electricity price is the biggest lever on running costs, and a cheaper rate cuts the bill in direct proportion. In Gareth’s example below, moving from 26.32p to an example heat pump rate of 15p lowers his yearly cost from £769.04 to £438.28.
Heat pump and time of use tariffs vary by supplier and change often, so 15p is only an illustration. Enter the average rate you would pay across the day into the heat pump running cost calculator. If part of your use is at a peak rate, weight the average towards the hours your heat pump actually runs.
VAT matters too. Gas cap rates include 5% VAT, while the 26.32p electricity cap rate currently has none, because VAT on household electricity is 0% from 1 October 2026 to 31 March 2027. If electricity VAT returns at 5%, rerun the sum.
Worked Example: Gareth’s Three Bed Semi
Gareth lives in a 1990s three bed semi in Swindon. His annual statement shows 11,000 kWh of gas and his combi boiler is about 85% efficient, so his heat demand is 9,350 kWh. His installer’s design gives a SCOP of 3.2, and he plans to cap the gas supply and stop paying the gas standing charge.
- Electricity: 9,350 kWh / 3.2 = 2,922 kWh
- Heat pump cost: 2,922 x 26.32p = £769.04
- Gas boiler: 9,350 / 0.85 x 7.97p + 365 x 29.68p = £985.03
- Saving: £215.99 a year
- Break even SCOP: 2.5
The heat pump running cost calculator tells Gareth he has a comfortable margin above break even. Capping the gas supply is a job for a Gas Safe registered engineer or the gas network, never a DIY task.
How Much Does a Heat Pump Cost to Install, and Are There Grants?
In England and Wales, the Boiler Upgrade Scheme on GOV.UK gives £7,500 towards an air source or ground source heat pump, with an extra £1,500 until March 2027 for some homes heated by oil or LPG without mains gas. Scotland and Northern Ireland run their own schemes.
Heat pump installation in homes in Great Britain is also zero rated for VAT until 31 March 2027. Install costs are not part of the heat pump running cost calculator and vary widely by home, so get quotes from MCS certified installers that include a heat loss survey. Our heat pump size calculator gives a first estimate of the kW output you need.
Common Mistakes When Comparing Heat Pump and Gas Costs
- Using gas kWh as heat demand. A boiler wastes part of the gas, so multiply by its efficiency first.
- Using the peak COP from a brochure instead of the seasonal SCOP.
- Counting the gas standing charge as saved while keeping a gas hob.
- Forgetting hot water, which a heat pump also has to heat, often at a lower efficiency.
- Comparing a new heat pump with an imaginary perfect boiler. Older boilers often run below their rated efficiency.
Rerun the heat pump running cost calculator with both a cautious SCOP and the design SCOP to see a realistic range. Insulation lowers heat demand for either system: the loft insulation calculator shows what material you need.
Do Heat Pumps Save Money in Ireland and the EU?
They can, and the heat pump running cost calculator works in euros too, but higher electricity prices raise the break even SCOP. Eurostat puts household electricity at an EU average of €28.96 per 100 kWh in the second half of 2025, €38.69 in Germany and €40.42 in Ireland. Switch the heat pump running cost calculator to your country, enter your local gas price in cents and see how the break even SCOP moves.
Heat Pump Running Cost Calculator FAQs
Is a heat pump cheaper to run than a gas boiler?
At October 2026 cap prices, a heat pump is cheaper than an 85% efficient gas boiler when its SCOP is above about 2.5 and you stop paying the gas standing charge. A heat pump tariff widens the gap; keeping gas for cooking narrows it.
What is SCOP on a heat pump?
SCOP is the seasonal coefficient of performance: the heat delivered over a whole year divided by the electricity used. A SCOP of 3 means 3 kWh of heat for every 1 kWh of electricity, averaged over cold and mild weather.
How do I work out my home’s heat demand?
Take your yearly gas use in kWh from your annual statement and multiply it by your boiler’s efficiency, for example 11,000 kWh x 0.85 = 9,350 kWh. A heat loss survey by an MCS certified installer gives a more precise figure.
Does a heat pump need to run all the time?
Not at full power, but the Energy Saving Trust advises keeping heating on for longer and lowering the temperature a few degrees when out, rather than switching off. A heat pump then avoids reheating a cold house, which helps its efficiency.
Can I keep my gas hob with a heat pump?
Yes, but you will still pay the daily gas standing charge, about £108 a year at the October 2026 cap. Set the standing charge saved to 0 in the heat pump running cost calculator to model this.
How much is the heat pump grant in the UK?
The Boiler Upgrade Scheme in England and Wales gives £7,500 towards an air source or ground source heat pump. Until March 2027 some off gas grid homes heated by oil or LPG can get an extra £1,500.
Checked October 2026. Sources: Ofgem energy price cap, Ofgem typical domestic consumption values 2026, GOV.UK Boiler Upgrade Scheme, Energy Saving Trust, HMRC VAT Notice 708/6, Eurostat.