Heat Pumps · Flagship calculator
Heat Pump Savings Calculator
Compare the annual running cost of an air- or ground-source heat pump against your current gas, oil, LPG or direct-electric heating. See payback period and CO₂ reduction — with editable prices, SCOP and grants.
Your home & heating
Rule of thumb: 100 m² well-insulated home ≈ 5,000–8,000 kWh · 150 m² older home ≈ 15,000–20,000 kWh.
EU grid avg 0.23 · UK 0.19 · Norway 0.02 · US 0.37
Annual running-cost savings
€561
You save vs natural gas at these prices.
Payback
21.4 years
Installed cost €12,000 ÷ annual savings.
CO₂ reduction / year
2,656 kg
= 2.7 tonnes · from cleaner electricity vs fossil combustion.
€1,667/yr
€1,105/yr
16,667 kWh
3,947 kWh
2.5 — you need SCOP above this to save
How the math works
The calculator is a direct energy-balance model — no fudge factors, no marketing assumptions. Two costs, one comparison:
Current cost/year = (heat demand ÷ boiler efficiency) ÷ kWh-per-unit × fuel price
Heat pump cost/year = heat demand ÷ SCOP × electricity price
Payback = installed cost ÷ (current − heat pump)
Heat demand is delivered heat into the home — not fuel input. If you only know last year's gas bill, multiply by boiler efficiency (typically 0.90 for a modern condensing gas boiler) to get delivered heat.
SCOP matters more than any other single input. Doubling SCOP halves the running cost. Realistic SCOP depends on flow temperature: low-temperature underfloor at 35 °C gives 3.8–4.5 for a good air-source unit; radiators at 55 °C typically give 2.8–3.4.
CO₂ savings use the emission factor of your grid — this is the single biggest driver of climate benefit. In Norway (near-zero grid), almost 100% of combustion CO₂ is avoided. In coal-heavy grids, savings are smaller but still positive versus gas because SCOP typically outpaces the CO₂ per kWh gap.