Free tool · Uses Q2 2026 unit rates

Heat Pump Running Cost Calculator UK 2026

Last reviewed · Compare vs gas, oil, LPG and electric heating

Enter your current heating fuel use and we'll show your annual cost on the standard Ofgem cap, Cosy Octopus, EDF Heat Pump Tracker and the British Gas heat pump tariff — alongside your current gas, oil or LPG cost. Real Energy Saving Trust SCOP figures, current BUS grant amounts including the July 2026 £9,000 oil/LPG uplift.

1. Your current heating

Typical UK gas household: 11,500 kWh. Find this on a recent bill or in your supplier's app.

2. Your home's likely SCOP

SCOP (Seasonal Coefficient of Performance) is the heat pump's real-world annual efficiency in your home. Based on EST's 2024 field trial of 742 UK installations.

3. Heat pump install assumption

How this calculator works

Heat demand calculation

We convert your current fuel use into useful kWh of heat using these efficiency factors:

  • Mains gas: kWh × 88% efficiency = heat kWh.
  • Heating oil: litres × 10.35 kWh/litre × 85% efficiency = heat kWh.
  • LPG: litres × 7.0 kWh/litre × 85% efficiency = heat kWh.
  • Electric storage: kWh × 100% = heat kWh (resistive heating is ~100% efficient).

Heat pump consumption

Heat pump electricity needed = heat kWh ÷ SCOP. SCOP values from the Energy Saving Trust 2024 field trial across 742 UK homes:

  • UK average: 2.9
  • Well-insulated: 3.4
  • Bottom quartile: 2.3
  • Ground source well-tuned: 4.0

Tariff rates used (Q2 2026)

Weighted effective rates assuming typical UK heat pump load profile:

  • Standard Ofgem cap (24.5p/kWh) — flat rate, no smart scheduling.
  • Cosy Octopus (~20p effective) — with ~50% consumption shifted into cheap windows (14.53p).
  • EDF Heat Pump Tracker (~21p effective) — cap-tracking with 6 hours/day at 10p below cap.
  • British Gas Heat Pump Tariff (~22p effective) — less aggressive peak-shifting.

Install costs (typical 2026)

  • Air source: £12,000 pre-grant.
  • Ground source: £25,000 pre-grant.
  • Air-to-air: £6,000 pre-grant.

What this calculator doesn't model

  • Insulation upgrades. If you improve insulation alongside the heat pump install, your heat demand falls (typically 15–30%) and the savings rise proportionally. We'd recommend running the calculator twice — once for current state, once for post-insulation state.
  • Hot water cost differences. A heat pump-heated hot water cylinder is ~3× more efficient than electric immersion but slightly less efficient than a gas-fired indirect cylinder. Net effect on total annual cost: ±£40.
  • Gas standing charge savings if you disconnect. Worth £117/year. We don't auto-include it because most heat pump households keep their gas supply for the hob.
  • Maintenance costs. Annual heat pump service costs are roughly equivalent to gas boiler service costs.
  • Real-time market price changes. The Q2 2026 cap is the basis. We'll update these unit rates after every Ofgem announcement.

Related

Check the grants you qualify for

A running cost calc is one piece. The other half is grants. Up to £30,000 of stackable funding for insulation + heat pump + solar — modelled against your specific household in 90 seconds.

Start the eligibility check →