The results from these product calculators should only be used as a rough guide as exact conversions will depend largely on a number of factors that are beyond Kelvin Timbe’s control. These vary from on site conditions such as: varying levels, moisture content of products, personal preference of desired amount of material to be used, individual’s percentage calculation of waste/damages and a number of further factors. Kelvin Timber cannot be held contractually responsible for any surplus or shortfall found on site. If in doubt speak to your sales representative who can advise on individual requirements to a greater extent, however, the final decision of the amount of material required will ultimately be the customers responsibility. If you are not sure always contact us first. Please remember also the calculators are mostly used for the materials we supply, if you are out with our delivery area please ensure to contact your local supplier first as dimensions may vary.