Heat Loss Calculator

The online Heatline Heat Loss Calculator is designed to give you an initial indication of the heating requirements within your home.



  1. Enter a name for your room (e.g. Master Bedroom or Spare Bedroom).
  2. Choose type of room (e.g. Bedroom, Kitchen, Living Room).
  3. Enter height, width and length details.
  4. Hit "Add room" button.
  5. Repeat process for all rooms in your home.
  6. Print out the details (PLEASE NOTE: your details are not saved and will be lost if you navigate away from the page).
  7. Contact your Gas Safe registered installer to discuss your exact heating requirements.





kW Total: 0


BTU's Total: 0


This tool is a basic heat loss calculator and is provided as a guideline only to indicate the likely size and type of radiator that could be used to heat a room according to your specification. This tool should not be used in isolation to size a heating system and Heatline accepts no liability for any incorrectly sized radiators or heating systems installed as a result of using this tool. To accurately calculate heat loss calculation or determine system sizing, a "Gas Safe" registered or competent installer should be consulted.