Calculating Radiator Sizes

A quick and easy way to calculate the size of the radiator required for any room in your house is by measuring the room in cubic feet and then applying the following factors to the figure arrived at:

Lounges and dining rooms          Multiply cubic feet by 5

Bedrooms                                    Multiply cubic feet by 4

Common areas and kitchens       Multiply cubic feet by 3

For rooms facing north                Add 15%

For French windows                    Add 20%

For double glazing                       Deduct 10%

This will give you the output of any radiator in BTUs (British Thermal Units). Adding the total for all the rooms in your house or flat  will give you the demand in BTUs for the whole house. Add 20% to the total for a hot water circulating tank and 10% for general losses. This will give you the boiler size you need for your house.

What size radiator do I need?:    Click here
What size boiler do I need?:       Click here

07958 500 900    020 8883 2223   020 3432 4146
               Mobile All Areas                       North London               South London & Surrey