Is there a standard height and depth for stairs?

Question

Is there a standard (or a standard range for) the height and depth of each step in a flight of stairs?

If your answer refers to your building code, please say where you live.

I was taught about 60 years ago that rise + run should be around 18 inches. — Hot Licks, May 17 '22 at 18:39

Doresoom · Answer 1 · 2013-09-17T23:01:13.440

30

The Stairway Manufacturing Code Association published the International Residential Code (PDF Link) in 2006 which tells you just about everything you could ever want to know about stairs, including:

minimum headroom depth (6' 8")
minimum tread depth (10")
maximum rise (7.75")
maximum tread depth variability (3/8")
maximum rise variability (3/8")
maximum slope of riser (30°)

edited Sep 17 '13 at 23:01

answered Aug 25 '10 at 22:46

Doresoom

15,584
29
79
117

Some building codes are more strict on variability than this. But in general it is a good guideline. +1 – ryanwinchester Aug 13 '14 at 16:03

score 29 · Accepted Answer · edited May 17 '22 at 18:10

29

The general rule (in the US) is 7-11 (a 7 inch rise and 11 inch run) (17.78cm-27.94cm). More exactly, no more than 7 3/4 inches (19.7cm) for the riser (vertical) and a minimum of 10 inches (25.4cm) for the tread (horizontal or step). You can find some more information here as well on other stair-related dimensions.

To calculate if the steps will be within the Building Codes specs: 2 times the step riser height + one tread depth equals between 24 and 25 in inches (60.96cm and 63.5cm).

example: (2 x 7.5") + 10 = 25 (2 x 19.05cm + 10 = 48.1cm)

edited May 17 '22 at 18:10

Community

1

answered Jul 22 '10 at 11:59

Eric Petroelje

9,631
7
39
62

4

This is true for a very specific sub-set: residential staircases. The reality is that there is no standard, though (as others note). It's the ratio that's dictated by code--not the specific rise/runs. – DA01 Jul 06 '14 at 04:25

score 14 · Answer 3 · answered Jul 22 '10 at 17:13

14

Not what you asked, but for safety the most important thing, even more important IMO than getting the right rise and run, is that every step is consistent. Varying as little as 1/4 inch in rise will make even a ballerina fall on her face if she's running up the stairs.

answered Jul 22 '10 at 17:13

Rod Fitzsimmons Frey

2,652
16
23

3

According to Sheldon Cooper, it's 2mm :) – Doresoom Jul 22 '10 at 18:46

score 4 · Answer 4 · answered Jul 22 '10 at 18:22

4

It not so much about the rise and run lengths specifically ,but about the ratio of the Rise to Run. You should strive to hit a 30-35% ration of rise/run. A 7-11 is the most common and gives you the correct ratio, but any combination of rise to run that hits this 30-35% ratio would be fine.

answered Jul 22 '10 at 18:22

mohlsen

6,221
14
37
44

1

Within reason, of course. You wouldn't want stairs that are 2 feet tall. :) – aphoria Jul 23 '10 at 00:51
4

I've actually taken to taking two steps at a time so 2 feet may not be that bad for me ;) – Wayne Werner Jul 23 '10 at 04:06
@Wayne.. wouldn't that be a little close to three stairs at a time? :) – warren Jul 28 '10 at 19:54
4

7-11 seems to me like 64% ratio of rise/run... – jkjenner Jan 20 '17 at 18:28
1

@jkjenner I think he is referring to 11*(1-0.35) = 7.15, not technically "ratio of rise/run". Should be "rise is 35% less than run" – Lombard May 11 '20 at 13:29

score 2 · Answer 5 · answered Jun 15 '13 at 11:36

2

As a general rule your stairs should be built with this in mind and you won't bust code no matter where you live. 2 risers plus 1 tread must equal a minimum of 24" and a maximum of 25" when added together. Example ( 2 risers of 7-1/4" = 14-1/2" then your tread could be 9-1/2" to 10-1/2").

answered Jun 15 '13 at 11:36

Roscoe

61
3

1

Where is this from? – Technophile Jul 14 '19 at 19:40

Is there a standard height and depth for stairs?

5 Answers5

Linked