The primary purpose of stairs is to provide a simple and easy means of moving between levels.

**Formula to calculate stairs.**

First, lets take a look at the regulations that are normally used in the construction of stairs.

**Example:**

Suppose you are supposed to put non spiral stairs on a floor of 750mm due to its change in level (rise). Since 2R + G = (550-700), calculate the number of steps and the slope relationship.

Since we know that the riser should be from 115 to 190, lets take 150mm to be our riser, therefore the number of steps needed is;

**= 750 **÷ 150

**= 5**

Therefore, 5 steps whose rise is 150mm should be constructed.

G should be between 240-355, so lets take 250 to be our going.

Slope relationship = **2R + G**

**= (2 x 150) + 250**

**= 550**

The slope relationship is 550. It is within the range 550-700 so it is acceptable.