A rule-of-thumb span-to-depth guide for timber or reinforced concrete beams. Use as a starting point only — always verify with a structural engineer.
Measurements
Minimum depth = span ÷ ratio, where the ratio depends on material and load:
For timber, a common guide width is roughly half the depth — this is indicative only.
Real designs must account for point loads, continuous spans, deflection limits, and local building codes.
Rule-of-thumb only — not a structural design. Beam sizing depends on load, support conditions, timber grade, steel reinforcement, and local codes. Always consult a qualified structural engineer before building.
