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Floor Joist Calculator – Joist Size & Span Calculator

Calculate floor joist size based on span and load requirements

Calculate Floor Joist
Table of Contents

How to Use

  1. Enter the span distance between supports
  2. Select joist spacing (12, 16, or 24 inches)
  3. Choose wood species and grade
  4. Select load type (residential or commercial)
  5. Click calculate to get joist size recommendations