We have included three concrete volume calculators for simple straight concrete stairs to help you in estimating the amount of concrete needed for your project.
To calculate the amount of concrete needed with this calculator for stairs, you need to know the rise, run, throat depth, and the width of the stairs.
The throat depth of the stairs is measured from the point where the rise and run cuts meet on the inside cut, to the compacted gravel, or inside form, below. As a standard the minimum throat thickness should be at least 152 mm.
This is not a very efficient way of building concrete stairs. I can see someone building stairs this way with 2 steps, but for more steps you would be better off building an inside box to limit the amount of concrete needed.
To use this calculator you need the enter the number of steps and include the landing as one of the steps. Enter the rise and run in millimeters, the width of the stairs and the desired length of your landing in millimeters.
For this type of stairs you would build an inside form to reduce the amount of concrete needed.
Enter the total amount of steps needed as the amount of actual steps and don't include the landing as a step. Then enter the rise, run and throat depth in millimeters. Width of stairs and length of landing need to be entered in meters. For number of walls you need to enter either a "1" or a "2" and the thickness of the wall in millimeters.