piped (central heating) or wired (electric heating)
calculator uniquely works for both piped : central heating (usually in BTUs) and wired : electric heating (usually in watts)
smart as gives real time answers as you input your data (not at the end) - so you can see how different factors affect the requirements
correct requirements
heat calculator to compute the correct output requirements to adequately heat your room then you can use the output filters on the listings pages to find products which match the output given: all piped designer radiators, all piped heated towel rails, all wired electric radiators, all wired: electric towel rails