Effective span of staircase

Effective Span of Staircase — Calculator

Choose case, enter dimensions (in metres unless otherwise specified). Effective depth d should be in metres (e.g., 0.15 for 150 mm).

Case Simply Supported Flight Cantilever Flight Flight Supported on Beams / Landing

Clear span between faces of supports (L_clear) — m

Clear distance between faces of supporting walls/beams

Support thickness / wall thickness (each side) — m

If supports differ, enter average or edit code — default assumes equal each side

Effective depth d — m

Effective depth (overall depth − cover − ½ bar dia)

Clear projection to face of support (L_proj) — m

Effective depth d — m

Is cantilever end of continuous member? No (use face rule) Yes (use centre of support)

Per IS-456 a cantilever effective span is taken as length to face plus d/2. If it is the end portion of a continuous member, take to centre of support (code exception).

Clear distance between beams (L_clear) — m

Effective depth d — m

Landing width (if flight bears onto landing) — m

Used for going + min(half landing width, 1.0 m) rule when relevant.

Going (horizontal projection of the flight) — m

If flight length (going) is used for landing-bearing rule.

Results update with MathJax typeset.

Results

Effective span (L_eff) = m

Notes:

• All inputs in metres. For mm values, divide by 1000 (e.g., 150 mm → 0.15 m).
• For simply supported: calculator assumes both supports equal thickness; edit inputs for different widths by adjusting/supporting centers manually.
• Calculator follows IS 456 style rules: simply-supported = min(clear + d, c/c supports); cantilever = face + d/2 (unless continuous end).