Standard Stair Step Height and Code Guidelines
By Stefan Gheorghe
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Stefan Gheorghe is the founder and CEO of Homedit.com. In 2008, he launched the platform out of his passion for interior design and home decoration.
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Stair dimensions are regulated for safety and consistency. Knowing the correct riser height, tread depth, and acceptable variation is essential when checking if your stairs meet code or planning a layout. Below are the standard dimensions used in most residential staircases, based on building code guidelines.
| Component | Standard Measurement (Residential) |
|---|---|
| Riser Height (Vertical) | Maximum 7¾ inches (197 mm) |
| Tread Depth (Horizontal) | Minimum 10 inches (254 mm), excluding nosing |
| Riser Height Variation | Maximum ⅜ inch difference between any two risers |
| Stair Angle | Typically between 30°–37° |
| Headroom Clearance | Minimum 6 feet 8 inches (2032 mm) |
| Stair Width (minimum) | 36 inches clear above the handrail |
These values follow the International Residential Code (IRC) used across most U.S. jurisdictions. Always confirm with your local building department to ensure compliance.
Key Terminology
- Riser: The vertical face between steps.
- Tread: The horizontal surface you step on.
- Nosing: The edge of the tread that may overhang the riser.
- Run: The total horizontal depth of one step.
- Total Rise: The total height from one floor to the next.
- Total Run: The total horizontal span of the staircase.
- Stringer: The structural side board that supports treads and risers.
- Headroom: The vertical space between a tread and the ceiling above.
Safety & Design Guidelines
- Keep all risers the same height to avoid trip hazards.
- Add a landing for staircases with more than 12 risers.
- Ensure proper lighting and install handrails.
- Use non-slip materials, especially on the treads.
Riser + Tread Rule of Thumb
A common formula:
- Riser height + Tread depth = 17″ to 18″
- Example: 7″ riser + 10″ tread = 17″
Standard stair dimensions exist to ensure safe, consistent use across homes. The measurements above reflect general code guidance, use them to evaluate existing stairs or when planning dimensions.