Roofing calculator is the ultimate tool for carpenters involved in making timber roofing structures. Simply enter the pitch and run to instantly get information including: - The rise of the common rafter per metre (or foot) of run. - The length of the common rafter. - The length of the hip. - Bevel angles including the seat and ridge for the rafter and hip/valley. - The jack rafter decrease based on industry standard centres. You can also input both IMPERIAL and METRIC units, and calculate using fractions of a pitch degree.