How much is a flight of stairs? And just why is it called a flight of stairs?
A flight is a metaphor for an ascent, but with the feet in place of wings. It is an uninterrupted sequence of steps. With this in mind, a flight of stairs typically contains 13 to 15 steps in homes with 8-foot walls.
Similarly, there will be 15–17 steps for a house with 9′ ceilings and 17–19 for homes with 10′ ceilings.
Let’s check out in detail what a flight of stairs means and how to calculate the number of steps in a flight.
What Does a Flight of Stairs Mean?
The phrase “flight of stairs” originates from a centuries-old French expression meaning “fly up steps.” The term “flight” denotes the capacity of a person to move swiftly or uninterruptedly up or down the stairs.
To put it simply, a flight of stairs means a landing without a break in the stairwell. However, flights must contain uniformly spaced and uninterrupted steps, but they are not required to have a specific number of steps.
Moreover, there is no set minimum or maximum for step lengths. A single flight may be straight, spiral, or curved.
How Many Stairs Are There in a Flight?
If the elevation of every step is 7.75 inches, then the total number of steps in a staircase leading to a room with a ceiling height of 8 feet is 14 steps.
The number of steps on a set of stairs is always divisible by the ceiling height, so a 9-foot ceiling means 16 steps. The 17 steps will be at 10′ ceilings.
The simplest method is to add the depth of the subfloor and the width of joists that hold the floor above together to get an approximate idea of the overall ceiling height, from which you can derive the total number of steps you’ll need.
Steps Required for 8′ Ceilings
For instance, the level above your home is supported by joists that are 10 inches broad and have 8′ ceilings. Joists are 9.25″ or 10″ wide.
Additionally, there is a 3/4″ flooring over those joists. Your stairway has a total rise of 8 feet and 10 inches between the first and last landing. To get 106, convert that sum to inches.
We’ll employ the 7.75″ maximum stair rise permitted by the IRC. You may get 13.7 by dividing 106″ by 7.75. You will therefore need to take 14 steps. To calculate the rise on every step, divide 106″ by 14; the result is 7.6, or roughly 7.96″ rise on each step.
Steps Required for 9′ Ceilings
Using the same measurements for the subfloor and joists as in the previous example, the total rise for a staircase in a home with 9-foot ceilings will be 118 inches.
The result of 118" divided by 7.75" is 15.2. If you want to take fewer steps when using stairs, you cannot just round down to 15. If you accomplished that, you would have the last step, roughly 4" long, which would be difficult and risky. You must round up and modify each step's climb proportionately.
Homes with 9′ ceilings require 16 steps to complete a flight of stairs. Divide 118″ by 16 to determine each step’s ascent. You receive 7.4 inches”. With this setup, you’ll have 16 steps, slightly about 7 1/2″ in height.
Steps Required for 10′ Ceilings
With the same measurements as above, 10″ broad joists, and a 3/4″ subfloor, you’ll have a rise of 130″. You get 16.8 when you divide it by 7.75″. Thus, there will be 17 steps required.
And to calculate the rise of each step, divide 130″ by 17 to determine each step’s ascent. The approximate height of each step is 7.7 inches.
What Is the Lowest Amount of Steps in a Flight?
However, there is no defined formula to calculate the lowest number of steps in a flight, but here’s a general rule of thumb.
There are enough steps for a secure flight of stairs because the building code specifies a maximum riser height of 7.75″. With the help of this figure, we can calculate the bare minimum of stairs that can be used in one flight.
For instance, the IRC stipulates that no floor or landing may have a steep increase greater than 12′. What is the smallest number of steps that can be taken over that distance? Let’s do the math.
To determine the bare minimum of stairs needed for a 12′ vertical increase, translate 12′ into inches (144). Next, divide 144″ by 7.75″, which results in 18.
To accommodate a 12′ vertical climb, you must have at least 19 steps. The stairs must end at the following floor after 19 steps, or there must be a landing before more steps can be taken.
The required steps to cover a vertical distance of any other length, say 9 or 10 feet, can be calculated by converting the distance to inches and dividing it by 7.75.
Final Words on Why It’s Called a Flight of Stairs
It is a lot of joy to take a staircase that does not end in a landing, sometimes known as a “flight of stairs.” Nevertheless, the total number of steps on each flight is determined by the height of the ceilings and the angle at which the stairs are oriented.
When using standard ceiling heights as an assumption, it is possible to calculate the total number of stairs in a flight. On average, it falls between 12 and 15 years old.