The BTU (British Thermal Unit) Calculator allows you to calculate an accurate estimate size for the wattage of heating required for any given space based on a number of parameters such as room size (including ceiling height), internal temperature, ambient temperature and the level of insulation. You can use this calculator to estimate the power of a heater needed to keep your room at a comfortable temperature.

How to use the calculator:

To find the power of the heater you need to give the dimensions of your room, specify on which floor it is and what type of insulation the walls have. If you are unsure which insulation type to choose, go for the worse insulation. It’s safer to be pessimistic.

You should also specify how many external walls there are. In the advanced mode, you can also include the number of windows and doors.

The last bit of the information needed is the difference of temperatures between inside (internal temperature) and outside (ambient temperature). The internal temperature depends on your comfort. The ambient temperature should be the minimum temperature occurring in your region.

With this information, we can compute the heat loss (in watts divided by the temperature difference). Knowing the heat loss, we can estimate the power of a heater.

Still not found the right size?

If you are struggling to find an accurate estimate for the power of heating required you can reach out to us using our Contact Form or by calling us on 0333 444 0899.