About this calculator

Rule of thumb: well-insulated EU home needs 35–50 W/m². COP for modern ASHPs averages 3.2 over a heating season. Sizing too big causes short-cycling.

Frequently asked questions

What does the Air-Source Heat Pump Sizing do?

Heat pump kW size and annual running cost for a UK/EU home. Rule of thumb: well-insulated EU home needs 35–50 W/m². COP for modern ASHPs averages 3.2 over a heating season. Sizing too big causes short-cycling.

Is the Air-Source Heat Pump Sizing free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Air-Source Heat Pump Sizing?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified heat pumps professional before committing to a purchase or a job.

What inputs does the Air-Source Heat Pump Sizing need?

Enter values for: Heated floor area (m²), Heat demand, Heating hours / yr, Seasonal COP, € / kWh electric. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Air-Source Heat Pump Sizing on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.