Interactive Roof Pitch, Rafter Span & Metal Roofing Squares Visualizer
Visualize roof pitch angles (2:12 to 16:12), calculate exact rafter and top-chord lengths, ridge height rise, truss counts, 36-inch metal panel sheet counts, and roofing squares with downloadable SVG cross-sections.
How to Use This Tool & Frequently Asked Questions
Tips for customizing dimensions, exporting vector .SVG files, and estimating build costs
How to Use This Tool & Frequently Asked Questions
Tips for customizing dimensions, exporting vector .SVG files, and estimating build costs
What is the best roof pitch for a barndominium or shop house?
A 4:12 roof pitch (18.4 degrees) is the industry standard for 30x40, 40x60, and 40x80 barndominiums and post-frame homes. It provides reliable snow and rain shedding for standing seam or 29-gauge metal panels while keeping truss manufacturing and steel framing costs economical.
How do you calculate rafter length from building span and roof pitch?
First divide the building width by 2 to find the half-span run, and add your horizontal eave overhang (typically 12 to 24 inches). Multiply that total run by the roof slope factor — equal to sqrt(1 + (Rise / 12)^2). For a 4:12 pitch, the slope multiplier is 1.054.
How many 36-inch metal roof panels do I need?
Standard ribbed post-frame and agricultural metal roof panels provide 36 inches (3 feet) of net weather coverage per sheet after overlapping the outer rib. Divide your total roof ridge length (building length plus both gable overhangs) by 3 feet, round up per roof plane, and multiply by 2 for a gable roof.
What is the difference between 26-gauge standing seam and 29-gauge ag metal roofing?
26-gauge standing seam metal is ~37% thicker steel and uses concealed clips so no screw heads are exposed to UV or thermal movement, lasting 50+ years. 29-gauge ribbed ag panels use exposed neoprene-washer screws that require inspection or replacement after 15 to 20 years, but cost roughly half as much upfront.