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Stair Stringer Calculator · Free calculator

Stair Stringer Calculator: 96" Total Rise

For 96" from finished floor to finished floor (8' 0"), you need 13 risers of 7-3/8" and 12 treads. With 10" treads the stairs run 10' 0" and each stringer is 12' 9-11/16" long — cut from a 14' 2x12.

Quick answer

Risers
13 × 7-3/8"
Treads (10")
12
Total run
10' 0"
Stringer length
12' 9-11/16"
2x12 stringers (36" wide)
3 × 14'
IRC
✓ Meets code

▍Stair Stringer Calculator

in
Tread depth (run)
in
Risers × height
13 × 7-3/8"
✓ Meets IRC (riser ≤ 7-3/4", tread ≥ 10")
8' 0"RUN 10' 0"
Treads
12
Total run
10' 0"
Stringer length
12' 9-11/16"
Angle
36.4°
2x12 stringers
3 × 14'
2R + T
24.77in

96" rise — tread depth options

TreadTotal runStringerAngle2R + TStock
10"10' 0"12' 9-11/16"36.4°24.7714'
10-1/2"10' 6"13' 2-3/8"35.1°25.2716'
11"11' 0"13' 7-3/16"33.9°25.7716'
1' 0"12' 0"14' 5-1/16"31.6°26.7716'

96" rise — riser count options

IRC R311.7.5.1: riser height 7-3/4" max. Comfortable stairs land at 7"–7-1/2".

RisersRiser heightTreadsMeets IRC
128"11No — too tall
137-3/8"12Yes
146-7/8"13Yes
156-3/8"14Yes

How the math works

  1. Risers = 96" ÷ 7.75" max = 12.39 → round up to 13
  2. Riser height = 96" ÷ 13 = 7.3846" ≈ 7-3/8"
  3. Treads = risers − 1 = 12
  4. Total run = 12 × 10" = 10' 0"
  5. Stringer = √(96² + 120.0²) = 12' 9-11/16"

Subtract one tread thickness from the bottom riser of the stringer (drop the stringer) so the first step matches the rest.

Trade pro tips

  • Measure the 96" rise from finished floor to finished floor — add flooring and tread thickness to rough measurements.
  • Cut one stringer, test it in place, then trace it for the rest.
  • At 36" wide, use 3 stringers; at wider than 36", add one stringer per 16"–18".

Frequently asked questions

How many steps for a 96 inch rise?

13 risers (steps up) of 7-3/8" each, with 12 treads. That stays under the IRC maximum riser height of 7-3/4".

How long of a stringer do I need for a 96" rise?

12' 9-11/16" along the slope with 10" treads (total run 10' 0"). Buy 14' 2x12s to leave room for the top and bottom cuts.

What is the riser height for a 96" stair?

7.385" — about 7-3/8" on the tape. 2R + T = 24.77", right in the comfortable range.

What angle are 96" stairs?

36.4° with 10" treads. Residential stairs typically fall between 30° and 37°.