Heat Pump Running Cost Calculator
See how a heat pump's yearly running cost compares to your gas boiler. Start from the gas use on your bill; the efficiency defaults are the ones measured in real UK homes, and the prices are the Ofgem price cap, 1 October to 31 December 2026, checked 20 September 2026.
Measured in real UK homes: bottom quartile 2.55, median 2.78, top quartile 3.05. A datasheet SCOP of 4+ is a laboratory figure.
Heat pump
£742
per year
Gas boiler
£865
per year, incl. standing charge
Heat pump saves
£123/yr
Break-even SPF at these prices: 2.38. A heat-pump tariff (e.g. Cosy Octopus) lowers the effective electricity price and moves this in the heat pump's favour.
Enter a postcode for your region's electricity rates. Cosy Octopus rates for your region.
Assumptions
- Heat pump efficiency
- Measured SPFH4 in 428 real UK homes: median 2.78, IQR 2.55–3.05 (Electrification of Heat)
- Boiler efficiency
- 82.5% measured mean across 31 combis (2009, small sample, least flattering to our own conclusion) (EST in-situ monitoring)
- Prices
- Electricity 26.32p, gas 7.97p + 29.68p/day standing charge, Ofgem price cap, 1 October to 31 December 2026; enter a postcode above the calculator for your region's Octopus rates (Ofgem)
- VAT
- Electricity is VAT-free until 1 April 2027; the saving falls when 5% returns
Rates checked 20 September 2026. Check them again before you commit to anything.