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Heat Pump Cost & Savings Calculator

Estimate current heating cost, likely heat pump electricity use, annual savings, grant-adjusted upfront cost, and simple payback.

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Published: 2026-01-01

Last updated: 2026-04-28

Last reviewed: 2026-04-28

Confidence: medium

Page review status

Written by: HeatWise Home Editorial Team

Reviewed by: Editorial review by HeatWise Home

Review status: Internally reviewed for clarity, source consistency, and calculation assumptions.

Expert review: Not currently externally expert-reviewed.

Last updated: 2026-04-28

Last reviewed: 2026-04-28

Confidence: medium

Sources:

External expert review: HeatWise Home does not currently publish named external expert reviewers. We are working toward adding independent review from qualified retrofit, heating, or building-energy professionals. Until then, users should treat our calculators and guides as educational planning tools and confirm decisions with official sources and qualified installers.

How to use this heat pump cost calculator

This calculator is designed for homeowners comparing an existing heating system with a future heat pump using their own assumptions for fuel price, annual heat demand, system efficiency, and grants.

It is most useful as an estimate-only planning tool before speaking to installers. For a buying decision, pair the result with a professional heat loss survey, emitter check, and live tariff review.

Helpful next step

See formulas, assumptions, and limits behind each estimate.

Read our calculator methodology

How the formula works

Current system input energy equals annual heat demand divided by current system efficiency. Current cost equals that input energy multiplied by your current fuel price.

Heat pump electricity use equals annual heat demand divided by SCOP. Heat pump cost equals that electricity use multiplied by your electricity price. Payback uses net installation cost after grants divided by annual savings.

Example calculation

If a home needs 12,000 kWh of heat and a heat pump achieves SCOP 3.2, estimated electricity use is 3,750 kWh.

At 30p per kWh, that is about GBP1,125 per year. If the current system costs GBP1,500 per year, estimated annual savings are about GBP375 before maintenance and other factors.

United Kingdom assumptions

Currency: GBP. Electricity: £0.25 per kWh. Gas: £0.06 per kWh. Heating oil: £0.11 per kWh.

  • Planning ranges: Electricity GBP 0.22-0.34 per kWh (Ofgem regional cap spread and available tariffs); Gas GBP 0.05-0.11 per kWh (Ofgem cap benchmark and regional/tariff variation); Heating oil GBP 0.09-0.13 per kWh equivalent (kerosene supplier tracking, delivery-size and season dependent).
  • Last checked: 2026-04-28. Confidence: medium.
  • Sources: Ofgem energy price cap and market data, GOV.UK Boiler Upgrade Scheme, MCS standards and UK building fabric guidance.

Caveat: prices vary by supplier, tariff, region, standing charge, and usage. Electricity/gas benchmarks align with Ofgem's 1 April to 30 June 2026 cap context (24.67p/kWh electricity and 5.74p/kWh gas GB average, Direct Debit) and broader tariff variation. Heating-oil range uses UK supplier-tracked kerosene pricing converted to kWh-equivalent planning values.

View calculator methodology

Current annual heating cost

£0

Estimated heat pump electricity use

4,375 kWh

Estimated heat pump annual cost

£1,094

Annual savings

-£1,094

This estimate suggests higher annual costs with a heat pump under the current assumptions.

Net installation cost after grants

£12,000

Estimated payback period

No simple payback

CO2 reduction estimate

2,067 kg/year

Recommendation summary

This estimate suggests limited or negative savings. Improving insulation, emitters, or tariff choice may be important before moving ahead.

Calculators on this site are estimates only. Always get a professional heat loss survey and verify current grant rules, tariffs, and product suitability before making purchase decisions.

Heat pump savings FAQs

No. These figures are estimates based on the assumptions you enter. Real-world results depend on design, controls, insulation, weather, and how the system is used.

Helpful next step

Adjust fuel prices, SCOP, grants, and costs using your own numbers.

Estimate your heat pump payback

Related tools and guides

Heat Pump Sizing Calculatorheat pump cost calculator for IrelandHeat Pump Grants GuideHeat Pump vs Gas Boiler

Methodology and assumptions

Review formulas, SCOP/COP context, fuel price assumptions, and limitations before relying on results.

Read calculator methodology

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Privacy and referral transparency

  • There is no obligation to proceed after you submit this form.
  • We do not routinely share your details with third parties.
  • Partner introductions only happen where relevant to your request.
  • Your data is handled according to our Privacy Policy.

What happens next:

  1. We review your question or quote request.
  2. We may reply directly or ask for missing details.
  3. If a partner introduction is relevant, we explain who the partner is before sharing your details.
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  5. Your data is handled according to our Privacy Policy.

If we suggest a partner

Where we suggest a partner, we aim to prioritise relevant, reputable providers or installers. We do not recommend proceeding without checking credentials, quotes, warranties, and official grant requirements.

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Occasional homeowner-friendly notes on heating costs, grants, insulation, and practical ways to lower bills.

Helpful next step

Pressure-test savings assumptions before committing to upgrades.

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