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).
Measuring for a carpet stair runner is surprisingly simple. Stair runners, usually sold by the running foot or yard, can be 22 to 36 inches wide. To calculate the length of the staircase for a runner, you need to measure the depth of the stair tread and the height of the stair riser. The tread is the flat horizontal board upon which you step.