How Many Stairs for a 9 Foot Ceiling?
Risers
16 at 7.31 in each
117 inches floor to floor, which is a 9 foot ceiling plus a 2x10 floor system and finish floor.
Two risers plus one tread is 25.13 in. Comfortable stairs land between 24 and 25.
How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Total rise, finished floor to finished floor117 in
- Tread depth you want10.5 in
- Stair width36 in
Risers16 at 7.31 in each
Two risers plus one tread is 25.13 in. Comfortable stairs land between 24 and 25.
| Total rise | 117 in |
|---|---|
| Number of risers | 16 |
| Riser height | 7.31 in |
| Number of treads | 15 |
| Total run | 157.5 in (13.13 ft) |
| Stringer length, minimum | 16.35 ft |
| Headroom needed above nosing | 80 in minimum |
The material list this produces
| Stringers, 17 ft | 4 |
|---|---|
| Treads, 36 in | 15 |
| Risers, 36 in | 16 |
Tread depth compared
Deeper treads are more comfortable and eat more floor. Same rise, four tread depths.
| Tread depth | Risers | Total run |
|---|---|---|
| 10 in | 16 at 7.31 in each | 150 in (12.5 ft) |
| 10.5 in | 16 at 7.31 in each | 157.5 in (13.13 ft) |
| 11 in | 16 at 7.31 in each | 165 in (13.75 ft) |
| 11.5 in | 16 at 7.31 in each | 172.5 in (14.38 ft) |
What else matters here
Sixteen risers at 7.31 inches, thirteen feet of run. Nine foot ceilings are common in newer construction and they add two risers and nearly two feet of run over an eight foot ceiling, which is more floor space than most plans have spare in the same footprint.
That is why nine foot ceilings so often come with a landing and a turn. A straight flight thirteen feet long plus landings at both ends needs about seventeen feet of clear length; an L shaped flight with a landing fits the same rise into a much shorter footprint.
If you are adding a landing, the landing is not a tread. It has its own minimum depth, normally at least as deep as the stair is wide, and the risers above and below it still have to be within three eighths of an inch of every other riser in the flight.
What this calculator assumes
- Riser count is the total rise divided by a 7.5 inch target, rounded to a whole number, and then increased by one if that would have put a riser over the code maximum. The rise is then divided evenly among them. Every riser in a flight must be within 3/8 inch of every other one.
- Treads are always one fewer than risers when the top riser lands on the finished floor above.
- The IRC limits are a 7.75 inch maximum riser and a 10 inch minimum tread. Your local code may be stricter, and commercial work certainly is.
Questions people ask
How many stairs for a 9 foot ceiling?
About 16 risers at 7.31 inches, based on a 117 inch floor to floor rise.
How much floor space do stairs for a 9 foot ceiling need?
About 157 inches of run, just over 13 feet, plus landings at both ends. That is why a landing and a turn is common at this height.
Does a landing count as a tread?
No. A landing has its own minimum depth, usually at least the width of the stair, and the risers above and below it must still match every other riser within three eighths of an inch.
The stair calculator takes any dimensions you like and hands back the same list.