Heat Pump Cost Calculator UK: Estimate Your Costs
Stop guessing — our free calculator narrows “somewhere between £10,000 and £18,000” down to a personalised range you can actually budget around, in under 60 seconds.
Every property is different. A well-insulated two-bedroom bungalow and a poorly insulated four-bedroom Victorian terrace will have vastly different costs. This guide explains how our calculator works, what inputs matter most, and walks through real examples.
Try the calculator now — free, instant results
Enter your postcode, property type, and current heating system. See your estimated costs, savings, and grant eligibility.
Calculate my costs →In this guide:
Why Use a Heat Pump Cost Calculator?
Average figures are misleading. A calculator that takes your specific inputs narrows the range dramatically — from “somewhere between £10,000 and £18,000” to “approximately £11,500 to £13,000.” That is a range you can plan around. For the wider cost context, see our complete heat pump cost guide.
Our calculator also estimates running costs and compares them to your current heating bills — often the more important number since running costs continue for 20 years.
How Our Calculator Works
Step 1: Estimating Your Heat Demand
Based on your property size, type, insulation level, and UK location. A well-insulated home might need 80 kWh/m²/year; a poorly insulated one might need 180+ kWh/m².
Step 2: Sizing the Heat Pump
Most UK homes need between 4 kW and 16 kW of heat pump capacity, with the majority falling in the 6–12 kW range.
Step 3: Estimating Installation Cost
Includes the heat pump unit, hot water cylinder, labour, pipework, electrical work, and base. The calculator then subtracts the BUS grant of £7,500 if you are eligible.
Step 4: Estimating Annual Running Costs
Using the formula: Annual cost = Heat demand ÷ Seasonal COP × Electricity price. We use realistic seasonal COP values (2.8–3.5 for air source), not peak marketing figures.
Step 5: Comparing to Your Current System
The calculator compares your estimated heat pump running costs to your current fuel — gas (6.76p/kWh), oil (6–8p/kWh), LPG (8–12p/kWh), or direct electric (24.50p/kWh at COP 1.0). For a detailed gas comparison, see our heat pump vs gas boiler guide.
What Inputs Matter Most?
Impact Ranking of Calculator Inputs
#1 Insulation Level
Highest Impact
Affects both installation and every year of running costs
#2 Property Size & Type
High Impact
Determines heat demand and unit size
#3 Current Fuel Type
Medium Impact
Changes the savings comparison
#4 Electricity Tariff
Medium Impact
Off-peak reduces running costs 15–30%
Example Calculations
| Detail | 3-Bed Semi (EPC C) | 4-Bed Detached (EPC D) | 2-Bed Bungalow (EPC B) |
|---|---|---|---|
| Heat demand | 9,500 kWh | 21,000 kWh | 5,600 kWh |
| HP size | 6 kW | 11 kW | 5 kW |
| Install (before grant) | £11,000 | £14,500 | £9,500 |
| After BUS grant | £3,500 | £7,000 | £2,000 |
| HP annual running cost | £810 | £1,725 | £490 |
| Current fuel cost | £715 (gas) | £1,890 (oil) | £420 (gas) |
| Annual difference | £95 more | £165 saving | £70 more |
Standard tariff rates. Off-peak tariffs improve all scenarios significantly.
Oil-heated properties often see the strongest financial case. For the well-insulated bungalow, the after-grant cost of £2,000 is less than a replacement gas boiler. Combining with solar panels can tip even the gas-heated examples into clear savings territory.
See your numbers — not these examples
Run the calculator now →Free. Instant results. No email required.
What the Calculator Cannot Tell You
No online calculator replaces a proper survey by an MCS-certified installer. Site-specific factors include: exact radiator condition, electrical supply capacity, pipework routes, access for the outdoor unit, and the specific brand recommended. We always recommend getting at least three quotes from vetted installers.
From estimate to reality — get 3 installer quotes
Connect with MCS-certified installers who will survey your property and provide itemised quotes with the BUS grant applied.
Get free quotes →No obligation. No sales calls from us.
Frequently Asked Questions
How accurate is the heat pump cost calculator?
Typically within 10–15% of the final installed cost for straightforward installations. Running cost estimates are usually closer to actual figures.
Does the calculator include the BUS grant?
Yes. If you indicate eligibility, the £7,500 grant is subtracted. See our grants guide for eligibility details.
What electricity price does the calculator use?
The default is the Ofgem cap rate (24.50p/kWh). You can override this with your actual tariff rate.
Can I use the calculator for ground source heat pumps?
Yes. Ground source has higher installation costs but higher seasonal efficiency, so running costs are typically lower. See our ground source guide.
Why does my estimate differ from quotes I have received?
Quotes include site-specific assessment and may include items the calculator cannot predict. Ask the installer to break down the costs so you can see where the additional expense lies.
Should I improve insulation before installing a heat pump?
In many cases, yes. Improving insulation reduces the required heat pump size, reduces running costs, and improves comfort. Our suitability checker can help assess this.
About Our Heat Pump Cost Calculator
Our free calculator uses established building physics and current 2026 market data to estimate heat pump installation costs, running costs, and savings for UK homeowners. It factors in property size, insulation level, current fuel type, and the BUS grant of £7,500. This tool is part of our comprehensive resource hub covering heat pump costs, air source systems, grants, and installation. For solar panel cost estimates to pair with a heat pump, visit Home Solar Guide.