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. Rise and Run means that a 6/12 pitch roof has 6" of rise (vertical) for each foot of run (horizontal). How to Measure and Cut Rafters. Calculate the length of a common rafter, and the length of a hip rafter based on the common rafter length. Hip Rafter Length Calculation building width in feet and inches (outside sheating to outside sheating) overhang in inches (from outside sheating to sub-fascia) ridge board thickness in inches wall + sheating thickness in inches. The standard roof rafter spacings measured on-center are 12″, 16″, 19.2″, and 24″. The International Residential Building Code (IRC), which is the basis of most North America’s building coide, identifies these standard industry measurements. Jul 21, 2022 · 7. Casio fx-300ESPLUS2 2nd Edition, Standard Scientific Calculator, Black. Natural Textbook Display- Can display fractions, derivatives, integrals, sum and other operations similar to their display in math textbooks. Converts between Standard form and a Decimal, Review/edit previous entries, Random Number Generator..