Heat Pump Calculator

Use this calculator to get an estimated heat pump size (in kW) for your swimming pool, hot tub or swim spa.

Just enter in:

  • Your pool or spa dimensions – length, width and average depth
  • Whether it’s indoor or outdoor, and if it’s fairly sheltered or exposed to the wind
  • Whether it’s in-ground or above-ground
  • How often you use a pool cover when it’s not in use
    Your swimming season (summer only, extended, or all year)
  • Your target water temperature – anything from a typical 26–30 °C pool right up to 40 °C for hot tubs and swim spas

Hit Calculate and the tool will give you:

  • The estimated water volume in m³ and litres
  • An estimated heat pump size in kW based on your answers

The calculator looks at your pool volume and conditions, then applies sensible rules-of-thumb to suggest a kW size that should be in the right ballpark for maintaining your chosen temperature in typical UK conditions.

Important: this is a guide only. It’s not a full heat-loss calculation and it doesn’t replace a proper design that takes into account pipework, electrics, hydraulics and how the pool is actually used.

Heat Pump Calculator

Pool Dimensions

Length (m) *
How long is your pool?
Width (m) *
How wide is your pool?
Depth (m) *
What is the average depth of your pool?
Estimated Volume
0.00
Litres

Further Information

Pool Location
Construction
Cover use
Swimming season
Temperature
0.00
Estimated heater size
0.00
KW

Pool or Hot Tub Volume

Litres
Enter the number of litres your pool or hot tub holds

Further Information

Pool Location
Construction
Cover use
Swimming season
Temperature
0.00
Estimated heater size
0.00
KW

Looking for an Indoor Pool Dehumidifier Calculator? Click here
What to do with your resultOnce you’ve got an estimated kW figure (for example, around 12 kW):
  • You can check it against a model you already had in mind, to see if you’re in the right area.
  • Or you can send us the result and let us recommend a suitable heat pump that matches your pool, budget and how you want to use it.
Bear in mind:
  • Hot tubs and swim spas running at higher temperatures (up to 40 °C) will naturally need more kW than a standard 28 °C family pool of the same size.
  • Outdoor, exposed and uncovered pools will need more heating power than sheltered, covered pools.
The calculator already factors these things in for you – so you don’t have to do the maths.

Want us to supply and install the right heat pump?

If you’ve used the calculator, have an estimated size, and would like to book in a site survey for a supply and installation quote please send us:

• Your calculator result (kW)
• A few photos of the pool and plant area
• Your postcode and a note on how you plan to use the pool or spa