Roof Rafter Length Chart

The length of the rafter.

Roof rafter length chart.

Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. Click the button to calculate the stock size needed for this job. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. 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.

For example if the ridge beam is 1 5 inches thick subtract 3 4 of an inch from the overall rafter length. 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. Here the number is 941 86 inches. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak.

The rise of the rafter. Here the number is 1166 66 inches. Includes result for hip valley factor slope factor and the roof slope in degrees. If you are calculating rafter length from the center of the ridge beam as shown below you will need to subtract half of the thickness of the ridge beam from the top end of the rafter.

Rafter length using angle v r 2cos a rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch. Input the rafter span on the flat eave overhang and pitch of the roof. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall.

Use our online rafter length calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead length of roof span pitch or angle. The run of the rafter. Height of the scaffold.