Stair Calculator

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

in
in
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

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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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