I'm adding steps from a house down to a patio and am trying to build the stringers:

  • 23.75" Total Rise
  • 12x2 nominal lumber for the stringers. Total of 4 stringers @ 48" wide
  • .92" composite treads
  • 11.75" tread depth (including the riser)
  • 1" nominal risers

With that rise including 3 steps, each step is 7.92" high. This is above the recommended 7.75". Will that be very difficult to use?

Also, does anyone have a good stair stringer calculator? I've tried a few but am seeing different results for each.

  • The difference between 7.75 and 7.92 is about 3/16 of an inch. Just saying.
    – Alaska Man
    Jul 4, 2020 at 19:11
  • Yeah, seems fine to me but I'm a total amateur. If it's better to add a riser, I'd rather do that. But that doesn't seem to work with the tread depth.
    – DIYoutube
    Jul 4, 2020 at 20:18

1 Answer 1


The maximum riser height allowed by Code is 8”. (See ICC R311.5.3.1)

The minimum riser height allowed by Code is 4”. (See ICC R311..5.3.4)

The maximum difference between the maximum height of any riser and the smallest allowed by Code is 3/8”. (See ICC R311.5.3)

Keep the maximum number of risers at 3 and you won’t be required to install a handrail.

Handrails are required when there are 4 or more risers. (See ICC R311.5.6)

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