Simply choose the correct units, key in your room measurements, and click the "Calculate" button to find the heat output required to adequately heat your room.

Stove kW Calculator
Room Width
Room Length
Room Height
Stove Output kW


How is The Output Calculated?

What would normally be regarded as a comfortable room temperature is around 21º/22ºC (70ºF). So let's say the temperature outside is , it would take about 1kW of heat for every 14 cubic metres of space to bring the room up to 21ºC.

1kW is the equivalent of approximately 1 bar on an electric fire.

Here is an example

To establish the cubic capacity of the room, multiply the length by width by height and divide the result by 14 for metres and 515 for feet.

Metres 6.5 4.5 2.4 70.2m³/14 5kW
Feet 21.5 15 8 2580 Feet³ /515 5kW


If the Stove Output calculation is too low for the Stove you like, remewber that you can control the heat with the level of fuel you add. With a little experimenting you will quickly find the fuel loading that is right for your comfort.

A small increase in the heat output may be required depending on the number of windows and doors and the level of insulation there is in the room.