How to Use a Framing Square to Build a Stair Case

Measure the overall height from the ground to the top of the staircase landing point with a tape measure. Divide the measurement by the average height of a stair riser---7 inches. For example, a height of 60 inches divided by 7 equals 8.57. Round the amount shown on the calculator to the nearest whole number---9 in this example.

Divide the overall height measurement by the number of steps to determine the rise of the staircase: 60 divided by 9 equals 6.67 or 6 11/16. Multiple the number of steps by 11.25 to determine the total run of the staircase: 9 times 11.25 equals 101.25 or 101 1/4.

Clamp one stair gauge on the short end of the framing square at the riser length you determined earlier. Clamp a second stair gauge on the long side of the framing square at the depth of the stair---11.25 or 11 1/4.

Lay the framing square over the face of a 2 by 12 board. Slide the framing square until both stair gauges sit tight to the front edge of the board. Slide the framing square until the short leg sits one riser height above the bottom of the board. Trace along the outside of the framing square to mark the first step on the board.

Slide the framing square until its short leg aligns with the stair depth line. Trace along the back of the square to draw the second step. Continue the process until you have all steps marked on the face of the board.