Stair Calculator
Lay out comfortable stairs from total rise to riser height, tread depth, and stringer length.
Riser height (in)
6.75
Breakdown
- Number of steps
- 16
- Total run (in)
- 157.50
- Stringer length (in)
- 190.97
- 2R + T (aim 24–25)
- 24
Last updated:
FAQ
What is a comfortable riser height?
Most building codes cap risers near 7.75 inches; 7 to 7.5 inches with a 10–11 inch tread feels best to most people.
What is the 2R + T rule?
Twice the riser plus the tread should land between 24 and 25 inches — an old carpenter's check for a comfortable stride.
Why is the top step one tread shorter?
The upper floor itself acts as the final tread, so a stringer with N risers needs only N−1 treads cut into it.
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