Stair Rise & Run Calculator
Calculate stair rise, run, and number of steps for code compliance.
Stair Rise & Run Calculator
What This Calculator Does
The Stair Rise and Run Calculator determines the number of risers, actual riser height, and total run for a staircase based on total floor-to-floor rise, target riser height, and tread depth. Enter the total rise in feet (floor to floor), and the calculator returns a code-compliant stair layout.
Stair design is governed by building codes that specify maximum rise, minimum tread depth, and the 7/11 rule (7-inch maximum riser, 11-inch minimum tread). The IRC (International Residential Code) limits riser height to 7.75 inches and requires minimum tread depth of 10 inches. Getting these numbers right is essential for both safety and code compliance - an incorrectly designed stair is a liability and a failed inspection.
The calculator starts with a default riser height of 7.5 inches and tread depth of 10 inches, both within standard code parameters. Adjust these values to match your specific requirements, and the calculator redistributes the dimensions to maintain a consistent, comfortable stair.
How to Use
- Measure the total vertical rise from finished floor to finished floor in feet.
- Set the target riser height (standard 7-7.75 inches) and tread depth (standard 10-11 inches).
- Enter all values into the calculator fields above.
- Click "Calculate" to see the number of risers, actual riser height, and total run.
- Verify the results meet local building code requirements before building.
Reference Table
| Floor-to-Floor | Risers | Riser Height | Total Run | Tread Depth |
|---|---|---|---|---|
| 8 ft | 13 | 7.38 in | 120 in | 10 in |
| 9 ft | 15 | 7.27 in | 140 in | 10 in |
| 10 ft | 16 | 7.5 in | 150 in | 10 in |
| 10 ft | 15 | 8.0 in | 140 in | 10 in |
| 12 ft | 19 | 7.58 in | 180 in | 10 in |
| 12 ft | 17 | 8.0 in | 160 in | 11 in |
Related Calculators
Frequently Asked Questions
📐 Measurement Tools
Explore all 15 measurement tools