Free tool · No signup
Stair rise + run code check
Check a stair's rise and run against the IBC and IRC requirements. The 4 inches of variation between adjacent risers / treads is the most common failure mode — we flag that explicitly.
Code result · IBC 1011.5
Riser height: PASS — 7″ vs max 7″Tread depth: PASS — 11″ vs min 11″Blondel's Rule: rise+tread = 18″ (in 17-18 range)
Uniformity rule (IBC 1011.5.4): within a flight, riser height variation ≤ 3/8″ and tread depth variation ≤ 3/8″. This tool checks one rise/tread pair — for flight-wide uniformity, measure every step and confirm the range.
Code references
- IBC 1011.5 (commercial): max 7″ riser height, min 11″ tread depth.
- IRC R311.7.5 (residential): max 7¾″ riser height, min 10″ tread depth.
- IBC 1011.5.4 (uniformity): riser height variation within a flight ≤ 3/8″; tread depth variation ≤ 3/8″.
- Rule-of-thumb: rise + tread should equal 17-18 inches (Blondel's Rule).
Built by Forward
Stair, ramp, fall-protection checks over text.
Forward runs IBC stair checks, ADA ramp slope checks, OSHA fall-protection thresholds, plus the NEC + IMC + IPC code calcs and the project-data lookups (RFIs, drawings, submittals) over a single phone number. No app, no login.