Joist Spacing Calculator | Free Construction Calculators

Calculate optimal joist spacing to achieve a desired span with given lumber size and loads.

About Joist Spacing

Joist spacing (on-center distance) directly affects the load each joist carries and its maximum span. Closer spacing allows longer spans with the same joist size but requires more material.

Design Verification Required

Always verify your framing design with local building codes and span tables. Professional engineering review is recommended for critical applications or unusual loads.