Heat pump running cost calculator (UK)
At the October 2026 cap, electricity costs 26.32p/kWh and gas 7.97p, so a heat pump has to deliver about 2.8 units of heat per unit of electricity just to match an 84%-efficient boiler. This calculator shows the break-even efficiency for your home and what changes it: your tariff, the standing charge and the grant.
From your bills or supplier app. Leave out gas used for cooking.
In the UK Electrification of Heat field trial, air source heat pumps had a median of 2.8 (middle half 2.5-3.1).
Use your heat pump or time-of-use tariff's average rate if you will switch.
If your boiler is due for replacement anyway, enter what a new one would cost.
Running cost comparison
- Heat your home needs
- 9,660 kWh
- Heat pump electricity
- 3,450 kWh
- Gas boiler cost per year
- £917
- Heat pump cost per year
- £908
- Running cost saving per year
- £9
- SPF needed to match gas cost
- 2.77
- Up-front cost after grant
- £5,408
- Payback on the up-front cost
- More than 50 years
Running costs only, at today's prices held flat. Insulation, emitter size and controls change real-world efficiency more than the heat pump model.
Defaults and sources
- Electricity price
- 26.32p/kWh and 54.83p/day standing charge: Ofgem price cap GB average, Direct Debit, 1 October to 31 December 2026 (no VAT on electricity this period)Ofgem, Energy price cap unit rates and standing charges · checked Oct 27, 2026
- Gas price
- 7.97p/kWh and 29.68p/day standing charge (Ofgem cap, Direct Debit, October to December 2026, includes 5% VAT)Ofgem, Energy price cap unit rates and standing charges · checked Oct 27, 2026
- Heat pump efficiency (SPF)
- Median SPF H4 2.80 for 291 air source heat pumps (interquartile range 2.53-3.09)Energy Systems Catapult for DESNZ, Electrification of Heat interim heat pump performance report (2023) · checked Oct 27, 2026
- Gas boiler efficiency
- 84% average fossil-fuel heating efficiency in the Electrification of Heat comparison (as reported by the Heat Pump Association)Heat Pump Association summary of the Electrification of Heat final report · checked Oct 27, 2026
- Installed heat pump cost
- Median £12,908 for air-to-water heat pumps installed April to June 2026 (including the grant value)DESNZ Boiler Upgrade Scheme statistics, August 2026, table Q1.1A · checked Oct 27, 2026
- Boiler Upgrade Scheme grant (England and Wales)
- £7,500 for an air or ground source heat pump; an extra £1,500 until March 2027 for homes heated by oil or LPG with no mains gasGOV.UK, Apply for the Boiler Upgrade Scheme: what you can get · checked Oct 27, 2026
How the calculator works
Heat needed is your gas use times your boiler's efficiency. The heat pump delivers the same heat using that amount divided by its seasonal performance factor (SPF) in electricity.
Running costs multiply each fuel by its price. The break-even SPF is the efficiency at which the heat pump costs the same to run as the boiler; above it you save. Payback divides the up-front cost after the grant (and any boiler replacement you avoid) by the yearly saving.
Heat pump running costs in the UK: common questions
Is a heat pump cheaper to run than a gas boiler in 2026?
Only if it is efficient enough. At the October-December 2026 cap (26.32p electricity, 7.97p gas), a heat pump needs an SPF of about 2.8 to match an 84%-efficient boiler, or about 2.5 if you also remove the gas supply and its standing charge. The UK field trial's median was 2.8, so tariff choice and good design decide whether you save.
How much does a heat pump cost to run per year?
A home using 11,500 kWh of gas needs about 9,660 kWh of heat; at SPF 2.8 that is about 3,450 kWh of electricity, roughly £908 a year at the cap. The same heat from gas costs about £917, plus £108 a year in gas standing charge if you keep the supply.
How much is the Boiler Upgrade Scheme grant?
£7,500 towards an air or ground source heat pump in England and Wales, plus £1,500 more until March 2027 for homes heated by oil or LPG with no mains gas. Scotland has its own grant and loan scheme.
How much does a heat pump cost to install?
The median installed cost of air-to-water heat pumps under the Boiler Upgrade Scheme was £12,908 in April to June 2026, including the grant value, leaving about £5,400 to pay after the £7,500 grant.