Stair Calculator – Calculate Rise, Run, and Number of Steps
The stair calculator computes optimal stair dimensions: rise (step height), run (step depth), and number of steps based on floor-to-floor height. Based on building code requirements.
Enter the height difference between floors, and the calculator will determine the number of steps, rise, and run within recommended limits. The tool also checks if your planned staircase meets standard building codes (rise + run = 24-25 inches).
What is a good stair rise and run?
International building codes: residential stairs typically have 7-8 inch rise, 9-12 inch run. The comfortable stair formula is: 2 × rise + run = 24-25 inches. Example: 7.5 inch rise + 10 inch run = 25 inches. Outdoor stairs should have lower rise (5-6 inches) due to slip hazards.
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Browse all tools →The stair calculator determines the number of steps, rise, and run based on the height difference and available space. A useful tool for builders and renovators in stair design.
Enter the height difference and available length, and the calculator determines the optimal number of steps and dimensions.
- Calculate the number of steps based on height difference.
- Get optimal dimensions for step rise and run.
- Check if the dimensions meet building code recommendations.
Stair dimensioning is based on the step rhythm rule, which ensures comfortable and safe walking.
- General step rhythm rule: 2 × rise + run = 590–650 mm.
- Typical rise height is 170–190 mm and run 250–300 mm.
- Stairs that are too steep or shallow are uncomfortable and can be dangerous.
Stair construction involves building codes that may vary depending on the intended use.
- Public spaces have stricter requirements than residential areas.
- Handrail requirements and height are determined by regulations.
- For complex projects, consult a structural engineer.