Calculate estimated roof load by combining roof dead load, roof live load, snow load, roof area, roof slope, rafter spacing, beam tributary width, and point loads. Use this roof load calculator for rafters, roof beams, ridge beams, headers, posts, footings, and preliminary structural planning.
Total roof load:
The calculator adds roof dead load, roof live load, and snow load, then applies the selected load factors.
Roof area:
The calculator can use plan roof area or sloped roof area based on the entered roof pitch.
Rafter line load:
The calculator multiplies total roof PSF by rafter spacing to estimate the load on each rafter.
Beam line load:
The calculator multiplies total roof PSF by tributary width to estimate the line load carried by a roof beam or header.
A roof load calculator helps estimate how much load a roof system, rafter, ridge beam, header, post, or footing may need to carry.
It can help compare roof area, slope factor, dead load, roof live load, snow load, total PSF, rafter PLF, beam PLF, total pounds, and support reactions.
Your result shows estimated roof area, slope factor, dead load, roof live load, snow load, total roof load in PSF, total roof load in pounds, rafter line load, beam line load, beam total load, and simple support reactions. These are planning estimates only.
Roof load is the weight carried by a roof system. It can include roof dead load, roof live load, snow load, equipment loads, and point loads.
Add the applicable roof loads in pounds per square foot, then multiply by roof area. For rafters or beams, multiply PSF by tributary width to get PLF.
Multiply roof load in PSF by rafter spacing in feet. For example, 35 PSF at 16 inches on center equals about 46.7 PLF per rafter.
Many structural load calculations use horizontal projected area, but material quantity and some weight estimates may use sloped roof area. This calculator allows either method for planning.