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WattWorth

Heat pump or gas boiler calculator

Compare the energy, running cost, emissions and simple payback for delivering the same amount of heat to your home.

Heat pump running cost a month

£94.00 a month

£1,128.00 a year, compared with £1,246.90 for the gas boiler.

2.8 is the current UK scheme minimum.

Electricity price

26.32p/kWh in the United Kingdom

Default Ofgem, 1 Oct – 31 Dec 2026.
Heat pump and gas boiler annual comparison
MeasureHeat pumpGas boiler
Running cost a year£1,128.00£1,246.90
Input energy a year4,286 kWh14,286 kWh
CO₂e a year932 kg3 t

£118.90 saved a year. Simple payback: 42.1 years. Break-even SCOP: 2.53. Emissions are 2.1 t lower a year.

How we calculated this

Both systems deliver 12,000 kWh of useful heat. The heat pump divides that by its seasonal performance; the boiler divides it by its efficiency.

The gas result includes its standing charge. The heat-pump result excludes the electricity standing charge because the home already needs an electricity connection.

Emissions use the regional electricity intensity and the 2026 UK government lifecycle gas factor.

Your prices

Every calculator uses these. They are saved on this device and nowhere else.

Pick where you live for your local prices.

Electricity

Default Ofgem, 1 Oct – 31 Dec 2026.

Default Ofgem, 1 Oct – 31 Dec 2026.

Gas

Default Ofgem, 1 Oct – 31 Dec 2026.

Default Ofgem, 1 Oct – 31 Dec 2026.