Answer
Worked out from a total rise of 96.00 inches, floor to floor.
Tread depth calculator
Tread depth11in11.000 in
- Total rise
- 96in96.00 in8 ft
- Tread run
- 11in
- Nosing
- 1in
Given
What this was worked out from
These are the figures every number on this page is worked for.
Solution
Every dimension of this flight
To the nearest sixteenth- Total rise
- 96in96.00 in8 ft
- Risers
- 14
- Riser height
- 67/878in6.857 in
- Treads
- 13
- Tread run
- 11in11.000 in
- Total run
- 143in143.000 in11 ft 11 in
- One step along the edge
- 1215/161516in12.962 in
- Marked length
- 1811/212in181.472 in15 ft 1.47 in
- Stringer length
- 1721/414in172.235 in14 ft 4.24 in
- Board length
- 16ft
- Angle
- 31.9°
- Stringer angle
- 33.9°
- 2 risers + 1 tread
- 2411/161116in24.71 in2 ft 0.71 in
- Bottom cut deduction
- 1in1.000 in
- Tread thickness
- 1in1.00 in
- Nosing
- 1in1.00 in
- Stair width
- 36in36.00 in3 ft
Options
What each tread run does to the flight
| Tread | 2R + T | Total run | Result |
|---|---|---|---|
| 10in | 2311/161116in | 130in | Within |
| 101/212in | 243/16316in | 1361/212in | Within |
| 11in | 2411/161116in | 143in | Within |
| 111/212in | 253/16316in | 1491/212in | Within |
| 12in | 2511/161116in | 156in | Within |
Cut the tread board 12.000 in wide to leave the nosing.
Code
Each figure against the limit it has to meet
| Dimension | Limit | Code | Result |
|---|---|---|---|
| Riser height, maximum | 73/434in | IRC 2021 (residential) | Within |
| Tread depth, minimum | 10in | IRC 2021 (residential) | Within |
| Stair width, minimum | 36in | IRC 2021 (residential) | Within |
| Riser height, minimum | 4in | ADA 2010504.2 | Within |
| Riser height, maximum | 7in | ADA 2010504.2 | Within |
| Tread depth, minimum | 11in | ADA 2010504.2 | Within |
| Nosing projection, maximum | 11/212in | ADA 2010504.5 | Within |
Calculators
Work out one part on its own
Source
Where the limits come from
2 sources, with the date each was read
- Code limits: IRC 2021 (residential), retrieved from https://www.co.routt.co.us/DocumentCenter/View/15202 on 2026-09-18. Numeric limits only; no code text is reproduced.
- Code limits: ADA 2010, 504.2, 504.5, retrieved from https://www.access-board.gov/aba/chapter/ch05/ on 2026-09-18. Numeric limits only; no code text is reproduced.
Building codes are adopted and amended locally. Confirm every figure with the code your jurisdiction has adopted before you cut.
Updated September 2026