Radiator Sizing

Guide to Sizing Radiators

Bascis understandig of terms

Heating Calculations..

To Understand how to work out the right heat output radiator for your room - this is a basic understanding on how to convert Kw enery to room sizes: -

1Kw of energy heats: -


The correct size radiator
Choosing the correct size radiator is important. This information provides you with a quick and easy method to estimate the best sized radiator for your home.


What to do:

  1. To estimate the size of the radiator required, you need to know how much heat is required to maintain a comfortable room temperature.
  2. Use the chart below to esitmate the heat required for each room.

Click on chart to down load PDF

The above chart is based on room assumptions of:

    A). The room being insulated to the new building code

      (If not, add 20% )


    B). The room having 25% or less of its walls as windows.   

    (If more than 50% of its wall as windows, ).

   C). The room ceiling height being 2.4 meters. 

      (If ceiling is higher add a percentage increase as below)

                    3 meters high    add 25%

                   3.6 meters high add 50%

Example: Room size 5 metres wide by 4 metres longwith ceiling height 3 metres

From the chart: Heat output = 2.3kW + 25% for 3 metre ceiling = 2.88Kw

 1.Windows are a significant loss factor, for every large window where the room has over 50% of its walls as windows space, please consult with Pivot Stove & Heating sales consultant