Beam Span Quick-Reference

Clear span

Member type

Suggested depth (rule of thumb)≈ 12.0–14.4 in

Depth (metric)≈ 30–37 cm

Span-to-depth ratioL/20 – L/24

Span24.0 ft

Using a span-to-depth ratio of L/20–L/24 for a steel beam.
Preliminary depth only — confirm with span tables or an engineer (not a code check).