Stair Calculator

Calculate rise, run, and number of stairs for any staircase.

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Guides & Reference

How It Works

Calculates steps: total rise divided by riser height. IRC code: riser max 7.75 inches, tread min 10 inches.

Formula

Steps = Total Rise / Rise

Quick Reference

Common calculations — results you can verify instantly.

9ft ceiling

108in/7in rise

15-16 steps

8ft ceiling

96in/7in rise

13-14 steps

Code max riser

IRC standard

7.75 inches max

Tips & Shortcuts

Comfortable formula: 2 x riser + tread = 24-26 inches.

Standard residential: 7-inch rise, 11-inch tread.

Common Mistakes

Using floor area instead of actual rise height

Measure actual vertical height from bottom floor to top floor.

Ignoring building codes

IRC max riser 7.75 inch, min tread 10 inch. Check local codes.

Frequently Asked Questions

108 inches / 7 inch rise = approximately 15-16 steps.

7 inches is most comfortable standard for residential stairs.

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