Calculate stair dimensions including rise, run, angle, and stringer length for any staircase.
| Dimension | Value | Code Limit | Pass? |
|---|---|---|---|
| Rise per Step | 7.71 in | 4" min – 7¾" max (IRC) | ✓ |
| Tread Depth | 10.00 in | 10" min (IRC) | ✓ |
| Angle | 39.72° | 30°–50° recommended | ✓ |
| Dimension | IRC Residential | OSHA Commercial |
|---|---|---|
| Max Rise | 7¾" | 9½" |
| Min Rise | 4" | 6" |
| Min Tread | 10" | 9½" |
| Min Width | 36" | 44" |
| Headroom | 6'8" | 7'0" |
| Handrail height | 34"–38" | 30"–38" |
Plan your staircase dimensions with our free stair calculator, calculating the ideal number of steps, rise, and run based on your total vertical height.
Number of Steps = Total Rise ÷ Ideal Individual Riser Height (commonly 7-7.75 inches). Once the number of steps is set, Actual Riser Height = Total Rise ÷ Number of Steps, and Run is typically calculated using standard comfort formulas (like rise + run = 17-18 inches).
Building codes commonly specify a maximum riser height (often around 7.75 inches) and minimum tread depth for safety and comfort, check your local building code for exact requirements.
Rise is the vertical height of each step; run is the horizontal depth of each step (the tread).
Building codes require riser heights within a specific range for safety, and all risers in a single staircase should be consistent to avoid trip hazards.
This calculator provides general guidance based on common standards; always verify against your specific local building code before construction.