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Stair Calculator

Calculate stair dimensions and check building code compliance.

Stair Calculator

Calculate stair dimensions and building code compliance

Formula

Risers = Total Rise ÷ Ideal Riser Height (7.5 in)

Checks IRC building code requirements

How to Use This Calculator

  1. 1

    Measure total rise

    Measure the total vertical distance from floor to floor.

  2. 2

    Measure available run

    Measure the horizontal space available for the stairs.

  3. 3

    Check code compliance

    Review the results to ensure they meet building codes.

Frequently Asked Questions

What is the ideal riser height?

Building codes typically require 7-7.75 inches. 7.5 inches is considered ideal for comfort.

What is the minimum tread depth?

IRC building code requires a minimum 10-inch tread depth for residential stairs.

What is the 2R + T rule?

The sum of twice the riser height plus tread depth should equal 24-25 inches for comfortable stairs.