### What Are Standard Stair Dimensions?

# What Are Standard Stair Dimensions?

**Standard stair dimensions usually depend on the desired level of comfort and ease of passage, ranging from 44” (112 cm) to 74” (188 cm). **

In public spaces a minimum of 44” (112 cm) is required, providing ample room for one person and allowing the tight passage of two people.

For comfortable two-person stair widths it is recommended to use between 49” (125 cm) to 60” (152 cm), while for three simultaneous users at least 74” (188 cm) must be used.

**What Are Standard Stair Rise And Run?**

**The OSHA and IBC regulations for stairs state that the rise should be a maximum of 9.5″ with a minimum tread depth of 9.5″, while the 2018 IBC building code states that the maximum rise should be 7″ with a minimum tread depth of 11″.**

This ensures safety for those climbing the stairs and helps reduce any potential falls or other injuries.

**What Are Comfortable Stairs Dimensions?**

**Comfortable stairs dimensions vary depending on personal preference, but we prefer a 32.6° angle or a 64% rise stairway with 11″ deep treads and 7″ risers. **

This combination of dimensions gives users plenty of space to ascend and descend without feeling cramped or unsteady. Using these measurements for your staircase offers an aesthetically pleasing result that also ensures safety and stability when navigating up and down the stairs.

Additionally, it is important to consider the height of the handrail which should meet local building codes as well as provide adequate elevation from the stairs for safe navigation.

**What Is The Formula For Stairs?**

**The formula for stairs involves dividing the height of a flight of stairs by 7 inches. For example, if the floor-to-floor distance is 8 feet, 10 inches (or 106 inches), then you’ll need 15 treads (106 divided by 7 equals 15.14). **

You then divide the height by the number of treads to get the exact tread height (7.06 inches). In this way, you can calculate how many steps and what size each step needs to be in order to construct a safe, sturdy staircase.

**What Is The Correct Angle For Stairs?**

**The correct angle for stairs is between 30 and 50 degrees relative to the horizontal, meaning that the sum of the rise and tread run dimensions should produce this angle. **

This standard must be adhered to ensure fixed stairs are compliant with safety regulations, as it ensures there is enough space to safely ascend and descend the staircase.

Failure to meet this requirement can put people using the stairs at risk, thus it is essential that any fixed stairway meets these standards.

**What Is The Minimum Width Of A Staircase?**

**The minimum width of a staircase depends on the occupant’s load. Stairways with more than 50 occupants must have a minimum width of 44 inches, while those with 50 or fewer, must have at least 36 inches. **

Private stairways with an occupancy load of less than 10 can have a width as low as 30 inches. All staircases must adhere to these standards in order to provide enough walking space and avoid any potential accidents.

**How Many Cm Are A Standard Stair Rise And Run?**

**A standard stair rise and run in the US generally follows a 7-11 rule, meaning a 7 inch (17.78cm) rise and an 11 inch (27.94cm) run. **

However, for more exact measurements, the riser should not be higher than 7 3/4 inches (19.7cm) while the tread must have a minimum of 10 inches (25.4cm).