Code limits and comfort
The US residential code (IRC) allows risers up to 7¾ in and treads of at least 10 in. A comfortable stair follows 2 × riser + tread ≈ 24 to 25 in (Blondel’s rule). Check your local code.
Example
A 108 in total rise needs 14 risers of about 7.71 in, with 10 in treads and a total run of about 10.8 ft.
These are estimates to plan your purchase. Check measurements on site and follow the manufacturer’s instructions and local building codes.
Frequently asked questions
Do I need a handrail?
Stairs with 4 or more risers generally need a handrail, usually 34 to 38 in high under the IRC.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.