This online calculator is designed to calculate the rafter length for the given dimensions of the roof of the building or a structure.
Rafter Length using Angle = V + R/(2cos(A))
Rafter Length using Pitch = V + (R/2)sqrt(1+P2)
- V – overhang
- R – roof span
- P – pitch
Note. This statistical rafter length calculator is provided for your personal use and should be used as a guide only. Construction and other decisions should NOT be based on the results of this calculator. Although this calculator has been tested, we cannot guarantee the accuracy of its calculations or results.