While not new, since the concept was already described by Christopher Alexander in its architectural theories, it only gathered some traction in programming due to the publication of Design Patterns: Elements of Reusable Object-Oriented Software book in October 1994 by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides, known as the Gang of Four (GoF), that identifies and describes 23 classic software design patterns.
Use a calculator to calculate the stair riser length or the number of steps you'll need. Divide the height from the first floor to the top of the second floor by a predetermined height of your choice for the riser. The typical height of a riser is 6 or 7 inches (15 to 17.5 cm).
Divide the total rise by the typical rise per step. This will give you the total number of steps on your stairs. The typical rise per step is about 7 inches (17.8 cm), but you'll probably use a different height in your final construction. So, if your riser is 7 inches (17.8 cm) tall, your tread should be anywhere from 9 to 11 inches (23 to 28 cm) long. 2  This makes the treads long enough to comfortably fit the average foot on and high enough to make stepping easy.