How to Measure Concrete Stairs

Measure from the ground straight up to the door's threshold and subtract 1 inch to account for slope. Divide this number by the amount of steps you want to determine the height of each riser.

Determine the depth of each tread, generally between 12 and 14 inches. The depth you choose depends on how much space you have available for the stairs. Steps with a 14-inch depth will extend farther from the door than steps with a 12-inch depth. Multiply the tread depth by the number of steps to find out how far the stairs will extend from the door.

Measure the width of the door opening, from the left side to the right side. Add 2 to 4 inches to make the stairs slightly wider than the opening. Multiply this number by the length the stairs extend from the door, which you figured out in Step 2. The answer tells you the stairs' square footage.

Enter the measurements from steps 1, 2 and 3 into the footing calculator found in the Reference section. The "depth" refers to a rise's height, the "width" refers to the tread's depth and the "length" refers to the square footage of the stairs. The calculator tells you how many bags of concrete you'll need to complete the project.