What are the maximum stair riser height and minimum tread depth?
IRC §R311.7.5model code
Max riser 7¾ inches, min tread 10 inches (IRC R311.7.5).
The IRC limits stair risers to a maximum of 7¾ inches (196 mm) and requires a minimum tread depth of 10 inches (254 mm).
The greatest riser height and tread depth within a flight can't exceed the smallest by more than 3⁄8 inch — consistency matters for safety and inspection.
Need this scoped to your jurisdiction?
Adopted edition and local amendments vary by city and county. Ask Donnie checks your jurisdiction and cites the exact adopted section.
Ask Donnie →General information based on the International Residential Code (a model code). This is AI assistance to verify — not legal advice. Confirm the adopted edition and any local amendments with your local building department (AHJ) and a licensed professional before you build.