Now you may use your device and a Google sheet (click this link to make a copy) to help with your calculations.
Calculating heat pump size: here’s a basic calculation from consumer.org.nz you can try for CL5.
Step 1 – Calculate the room’s volume in cubic meters.
Step 2 – Multiply that by 44 watts.
Step 2 - Add 10% to large window areas and a further 10-20% for partial or no insulation.
Step 3 - Multiply this figure by 1.5 for living areas, 1.2 for a bedroom, and 0.8 for other areas.
Example: A partially insulated lounge, 4m x 5m x 2.4m high + 10% for lack of insulation = 53 cubic metres room volume (rounded up). Multiply by 44watts = 2332, now by 1.5 because it’s a lounge = 3498 watts. This means you will need a 3.5kW heat pump.