Calculate the number of steps. A natural step height (rise) is 7 1/2 inches. If your total rise is 22 1/2 inches, you will need three rises (22 1/2 inches divided by 7 1/2 inches) and two stairs. You will always have one fewer stair than the number of rises. A standard brick measures 8x4x2 1/2 inches (8 inches long by 4 inches wide by 2 1/2 inches high). A natural step would use a one brick riser between every stair. You can make shorter steps using stones with a 1 1/2-inch height in place of the bricks, but the stair should be deeper to accommodate an extra pace for each step.
Calculate the number of bricks needed for your stairs. Your stair needs to be a multiple of the brick or stone dimensions. If you use standard bricks, three bricks wide by two bricks deep yields a stair that is 12 inches wide and 10 inches deep with a 2-inch lip. (Note: The riser sits on 4 inches of the stair.) Each stair requires six bricks and you need two stairs, for a total of 12 bricks for the stairs.
Calculate the number of bricks you need for your risers. With a 7 1/2 inch step height, you will need one brick riser that is three bricks across. You need three risers, for a total of nine bricks for the risers. Based on these dimensions, you will need a total of 21 bricks for your steps.
Calculate the amount of cement needed for your brick staircase. You need the total square footage of the stairs to determine the cement required for your staircase. Your stair is three bricks wide (or 12 inches) and two bricks deep (or 16 inches). The total area of each stair is 12 inches times 16 inches, or 192 inches (or 1.33 square feet). You have two stairs to cement, for a total of 2.66 square feet. You need to add 50 percent for waste and the risers. You need enough cement to cover 4 square feet.