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Stair Calculator

Enter the total rise and your target riser height to get the number of steps, exact riser height, and total run.

Your numbers

in
in
in

Steps (risers)

14

Exact riser height
7.71 in
Treads
13
Total run
130 in
Stair angle
37.6°

Results are estimates for planning. Check important figures with a qualified professional.

Quick answer

The Stair Calculator shows number of steps, riser height, and total run for a staircase. How it works: Risers = total rise ÷ max riser, rounded up; Riser height = total rise ÷ risers. For example, with total rise (floor to floor) of 108 in, max riser height of 7.75 in, and tread depth of 10 in, the steps (risers) is 14.

How to use the Stair Calculator

  1. Enter total rise (floor to floor).
  2. Enter max riser height. The IRC limit for homes is 7 3/4 inches (19.7 cm). Check local code.
  3. Enter tread depth.
  4. Read steps (risers) and the breakdown. Use Share to send the exact numbers, or Print to save a PDF.

How it's calculated

  • Risers = total rise ÷ max riser, rounded up
  • Riser height = total rise ÷ risers
  • Total run = (risers − 1) × tread depth

Worked example

With total rise (floor to floor) of 108 in, max riser height of 7.75 in, and tread depth of 10 in:

Steps (risers): 14. Exact riser height: 7.71 in.

Questions people ask

Why one fewer tread than risers?

The top step is the upper floor itself.