A total rise of 96" (8 ft) takes 13 risers of 7 3/8" each. That is 96" ÷ 7.75 = 12.39, rounded up to 13: the fewest risers that keep every step at or under 7 3/4", the residential maximum in IRC R311.7.5.1. With 13 risers you build 12 treads, because the top floor or deck is the last step. At 10" per tread, the IRC R311.7.5.2 minimum, the stair runs 10' 0" from the face of the first riser.
The usual comfort check, 2 × riser + tread, comes to 24.8" with 10" treads, inside the 24" to 25" range that feels natural. One more riser (14 of 6 7/8", 13 treads) makes each step lower and stretches the run to 10' 10".
Stringers and slope
One riser and one 10" tread make a step 12.43" long on the slope: √(7.385² + 10²). Times 12 treads, each stringer measures 12' 5 3/16" along its top edge, so with about a foot extra for the plumb and level cuts it comes out of a 14 ft board. The stair climbs at 36.4°. Cut stringers are usually 2×12s; the stair calculator lays out every mark for the framing square.
Riser options for a 96" rise
Riser options for a 96" rise| Risers | Riser height | Treads | Total run | 2R + T |
|---|
| 13 | 7 3/8" | 12 | 10' 0" | 24.8 |
|---|
| 14 | 6 7/8" | 13 | 10' 10" | 23.7 |
|---|
| 15 | 6 3/8" | 14 | 11' 8" | 22.8 |
|---|
Nearby total rises (10" treads)
Nearby total rises (10" treads)| Total rise | Risers | Riser height | Treads | Total run |
|---|
90"
7' 6" | 12 | 7 1/2" | 11 | 9' 2" |
|---|
92"
7' 8" | 12 | 7 11/16" | 11 | 9' 2" |
|---|
94"
7' 10" | 13 | 7 1/4" | 12 | 10' 0" |
|---|
96"
8' 0" | 13 | 7 3/8" | 12 | 10' 0" |
|---|
98"
8' 2" | 13 | 7 9/16" | 12 | 10' 0" |
|---|
100"
8' 4" | 13 | 7 11/16" | 12 | 10' 0" |
|---|
102"
8' 6" | 14 | 7 5/16" | 13 | 10' 10" |
|---|
Measuring and code notes
Measure the total rise from the finished surface where the stair lands (floor, pad or patio) to the finished upper floor or deck. If the ground slopes, run a level line out from the deck to where the bottom step will land and measure down from there, not at the deck edge. Count flooring that is not down yet.
IRC R311.7.5.1 also keeps the tallest and shortest riser in a flight within 3/8" of each other, and R311.7.8 calls for a handrail on at least one side of any flight with four or more risers. Local codes can be stricter; check with your building department before you cut.
Frequently asked questions
How many steps for a 8 ft rise?
13 risers of 7 3/8" and 12 treads. People often count steps as risers; the last one lands on the upper floor or deck, so you build one tread fewer than risers.
How long is a stair with a 96" rise?
10' 0" of total run with 10" treads, or 11' 0" with 11" treads (12 treads either way). Leave room for a landing at the bottom too: IRC R311.7.6 asks for one at least as wide as the stair and 36" deep in the direction of travel.
Does a stair with a 96" rise need a handrail?
Under the IRC, yes: it has 13 risers, and R311.7.8 calls for a handrail on at least one side of any flight with four or more risers. Check your local code for the height and grip size.
Estimates only. Check measurements, product labels and local building codes before you buy or build.