Roof Truss Span Chart
A truss span chart is a quick reference table showing typical maximum spans for common chord sizes and spacings before an engineer finalizes a design. Use the table below for a first estimate, then the calculator above for your exact span, pitch, and load.
Calculate Your Exact Span
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How to Read a Truss Span Chart
Published span charts (commonly from the American Wood Council's span tables, or a truss manufacturer's technical data) cross-reference lumber size, grade, spacing, and load to give a maximum allowable span. Wider spacing or heavier load always lowers the maximum span for a given chord size.
These charts are a starting estimate, not a final design — truss span capacity also depends on web configuration, connector plate size, and lumber grade (No.1, No.2, or Select Structural), none of which a simple chart captures. A stamped, engineered truss drawing is always the final word for a permitted structure.
Use this page's calculator to check your specific span, pitch, and spacing combination, then cross-reference the general ranges below as a sanity check before requesting a formal quote.
Frequently Asked Questions
What is a truss span chart used for?
A truss span chart gives a quick, general estimate of the maximum span a given chord size and spacing can typically handle, useful for early planning before a truss manufacturer provides an engineered design.
Are span chart numbers exact?
No — span charts show general ranges based on typical lumber grade and load assumptions. Actual maximum span depends on your specific load, spacing, web design, and lumber grade, and should be confirmed with a stamped engineered truss design.