Floor Joist Calculator

    Size floor joists for span and load

    ft

    Formula

    Min Depth ≈ Span × 0.6"

    Floor joist sizing depends on span, spacing, and load.

    Examples

    14ft span, 16" OC

    2×10 joists recommended.

    Frequently Asked Questions

    About Floor Joist

    Size floor joists for span and load.