Our roof rafter calculator tools are handy for calculating the number of rafters needed, rafter length calculator, lineal feet of rafter, board feed in ridge and sub-facia,and the total board feet in the roof.. Rafter calculator instructions enter the value for the roof width (outside to outside) in feet, inches, and fraction, inches and fraction, or use the inches box to enter a value in decimals if that is your preference.. When building a roof, how do you calculate the length of the rafters? all you need to know are the span of the building and the slope of the roof..
To increase the use of wood by assuring the broad regulatory acceptance of wood products, developing design tools and guidelines for wood construction, and influencing the development of public policies affecting the use and manufacture of wood products.. The roof pitch calculator calculates slope, pitch, angle and rafter lengths, based on input of rise (m) and run (r). use the diagrams on this page as a reference when inputting rise and run, and while interpreting the calculated results. angle - the angle of a roof is the same as the roof's slope. You don't need a framing square or rafters to calculate the rafter lengths, you can do it all on paper allowing you to calculate all the materials needed to price the job accurately just by knowing the size of the roof and the centres for the rafters..
