StairBuddy

Interactive stair planning tool for residential construction

Stair Inputs

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Auto-calculated for comfort

Construction Style

1.5" thick, 1 board per tread

Best for interior stairs — single solid board.

At edgesUnder treads

Mounting

Quick Presets

IRC Code Compliance

0 Passing
0 Warnings
0 Failing
Disclaimer: This tool provides guidance based on International Residential Code (IRC). Always consult local building codes and have your plans reviewed by a licensed professional.

About StairBuddy

StairBuddy is an interactive stair planning tool designed for residential construction, particularly deck stairs and similar structures. It helps ensure your stairs meet IRC (International Residential Code) requirements before you begin construction.

Key Features:

  • Real-time IRC building code compliance checking
  • Visual stair profile and cutting patterns
  • Comfort metrics based on industry standards (Blondel formula)
  • Support for 3-20 step configurations
  • Stringer cutting patterns for 2×12 lumber

IRC Requirements:

  • Maximum riser height: 7¾ inches
  • Minimum tread depth: 10" (with nosing) or 11" (without)
  • Maximum riser variance: â…œ inch within a flight
  • Handrail required for 4 or more risers

Important Disclaimer:

This tool provides guidance based on the International Residential Code. Local building codes may vary. Always consult your local building department and have your plans reviewed by a licensed professional before construction. This tool is for planning purposes only and does not replace professional engineering or architectural services.

Glossary of Terms

Riser
The vertical portion of a step, measuring the height from one tread to the next.
Tread
The horizontal surface of a step where you place your foot.
Nosing
The protruding edge of a tread that extends beyond the riser. Typically 3/4" to 1-1/4".
Stringer
The structural support that runs diagonally along the sides of the stairs, typically cut from 2×12 lumber.
Unit Rise
The height of a single riser (Total Rise ÷ Number of Steps).
Unit Run
The depth of a single tread.
Total Rise
The total vertical height from the bottom landing to the top landing.
Total Run
The total horizontal distance the stairs cover.
Blondel Formula
A comfort formula for stairs: 2 × Riser + Tread ≈ 25 inches. Named after French architect François Blondel.
IRC
International Residential Code - a model building code for residential structures.