The general rule for standard stair dimensions that is accepted by many general contractors and stair designers across the United States is known as the “7-11” rule. This means the rise is 7 inches and the run is 11 inches.
Ratio between height (rise r) to width (tread t) of the step. This follows the golden rule which is: 2 x r + t = 63 cm. i.e.: 2 times the rise plus the tread equals 63 cm with a maximum variation of ± 1 cm.
ADA – Similar to IBC, the ADA requires stairs to have risers no higher than 7 inches and tread depths of at least 11 inches, ensuring a slope that typically aligns with IBC standards of around 30 to 37 degrees.
What is code for rise and run of stairs? The 2018 IBC building code for rise and run of stairs is a maximum 7″ rise and minimum 11″ run (tread depth). The OSHA standard for rise and run of stairs is maximum 9.5″ rise and minimum 9.5″ run (tread depth). The IBC maximum rise of a single stair flight is 12.
The "27 Rule" for stairs is a helpful guideline for determining comfortable stair dimensions. According to this rule, the sum of the riser height and the tread depth should equal 27 inches. For example, if the riser height is 7 inches, the tread depth should be 10 inches.
The old-fashioned rule was that a lady would precede the gentleman up the stairs in case she were to fall -- ensuring that he could then assist her.
Stringer framing should always be cut from a 2x12, by the way. I have seen them cut from 2x10 and even 2x8 before for some ridiculous reason. DON'T DO IT!
Research shows that a rise plus run (r+R) of 46cm is a comfortable stride for most people. Less than 43cm will require strides that will be too short for most people, while more than 48cm will likely be too much of a stretch.
Standard Stair Riser Height
Standard stairs must have a maximum riser height of 9.5 inches (24 cm) following OSHA 1910.25(c)(2). IBC 1011.5. 2 stipulates that the minimum and maximum stair riser heights must be 4 inches (10.16 cm) and 7 inches (17.78 cm), respectively.
The complete answer is that the formula for stairs is 2R +T = 26–27″. R is riser height, T is tread length. For example, if you want 6" risers, 2×6" =12″ ; so the tread length should be 14–15″.
The Golden Ratio is a mathematical equation that has been used by designers for centuries to create aesthetically pleasing proportions. According to the Golden Ratio, the ideal step size for a staircase is 2.618 times the height of the riser.
Riser Heights for People of Limited Mobility
If there is a senior using the stairs, it's recommended that the step height standard be a little less than normal, such as a maximum of 6 7/8 inches.
The stair angle may be determined by the minimum tread depth and maximum riser heights. For IBC commercial stairs, the minimum tread depth and maximum riser height is 7 inches and 11 inches. These tread and riser dimensions require the stair to have a 32.4 degree angle.
The IRC stairs code states that, to comply with stairway requirements, the minimum width for residential stairs be no less than 36 inches. The stair riser code is up to 7.75 inches, and can not vary more than 3/8 of an inch. There are also section codes in place for standard stair tread dimensions.
Crossing on the stairs invokes bad luck
Many believe that crossing someone on the stairs will bring you bad luck. The origin is down to suggestions rather than anything else; some say it was before the stair bannister was invented, and crossing on the stairs could lead to one person falling off.
The maximum riser height is 7.75 inches, with a similar maximum permitted variation of ⅜ inch in any single stairway. Risers must be vertical or have a maximum slope of 30 degrees from vertical. Stair dimensional requirements from the 2021 IRC.
Typically, the standard size of steps is around 7 inches in height (rise), 9-10 inches in depth (run), and 22-36 inches in tread length for maximum convenience among family members of all ages. However, checking your local building codes can sometimes provide a more specific size recommended for your home!
With regard to the standard height of a staircase riser, the measurement is often between 6-1/4 and 7-7/8 inches. With respect to the step run, this measurement is between 8-1/4 and 12-1/2 inches. However, one very important aspect is the uniformity of your measurements.
The "27 Rule" is a handy way to figure out how deep and tall each step should be. According to this rule, if you add the height of the riser (the vertical part) and the depth of the tread (the horizontal part), it should equal 27 inches.
Sum of two risers plus tread width = 24 in. to 25 in. An “ideal” ratio is 7 in. rise and 10 in. tread.
Remember that your stairs are grandfathered in as long as you don't alter the rise and run. In other words, it's not the actual stairs that matter, but the existing measurements.
Stability is crucial when making deck stairs, so you must attach supports. From the back, screw a piece of 2x6 horizontally along the width of all stringers. Then, take two more pieces of 2x6 and fix them vertically, attaching them to the back of the deck rim and the first piece of 2x6.
Average Height of a Stair Riser
The typical stair riser height is 200mm. This is considered the ideal height for stair risers as it yields the most comfortable step while also conforming to safety standards.
The easiest way to attach stair stringers to a deck is to use hangers or lag bolts to attach them directly to the rim joist.