Shed Roof Truss Calculator
A shed roof truss uses a single sloped plane running from a tall wall to a short wall — the standard framing for storage sheds, workshops, and small outbuildings. This calculator sizes a shed roof truss from your span and pitch, returning rafter length, roof area, and material cost.
Size Your Shed Roof Truss
Enter your building specifications below. Results and the roof diagram update live as you type.
Live Roof Diagram
Results
Estimate Your Project Budget
Automatically calculated from your inputs above in the calculator.
Estimates only. Actual costs vary by region, supplier, and site conditions.
Building a Simple Shed Roof
A shed roof is the simplest roof shape to frame — one continuous slope, no ridge, no valleys, and no hip corners. For small outbuildings (typically under 16 ft span), many builders use single rafters rather than pre-built trusses, since the shape is simple enough to cut on site.
Shed roof pitch is usually shallower than a house roof, commonly 1/12 to 4/12, since the structure is smaller and a very steep slope wastes material and headroom on a small building. Confirm your local snow load before going below a 2/12 pitch, since low slopes shed snow more slowly.
Use this calculator with your shed's span (the distance between the two side walls) and desired pitch to get rafter length and an estimated material list before starting the build.
Frequently Asked Questions
What is a good pitch for a shed roof?
Shed roofs commonly use a 1/12 to 4/12 pitch — steep enough to shed water, shallow enough to conserve material on a small structure. Check local snow load requirements if you plan to go below a 2/12 pitch.
Do small sheds need engineered trusses?
Most sheds under about 12-16 ft span use simple stick-framed rafters rather than pre-built trusses, since the shape and load are simple enough to build without factory engineering — check your local permit requirements first.