No matter what the nature of a brickwork project, calculating the number of bricks per square foot helps determine how many bricks are needed for the project as a whole. You also need to know the square footage of the area where the bricks are needed, such as a wall or a patio. Once you've calculated these figures, you can estimate the amount of bricks needed. Include 5 to 10 percent of overage as well, in case of breakage or damaged bricks.
Measure the length and width of one brick with a tape measure. Multiply the length and width, such as 4 inches wide by 8 inches long, to get the total square inches. Note: This is for bricks that will install with their broad faces up, as with patio pavers. If the bricks will install with their front faces exposed, as with standard wall brick, measure the length and the height, not the width.
Divide the total square inches into 144, which is the total number of inches in a square foot. If the brick is 32 square inches, for instance, the result is 4.5 bricks per square foot (144 divided by 32).
Measure the length and width of the project space, such as a patio or wall 10 feet high, 12 feet wide. The resulting number -- in this case, 120 -- is the square footage of the project space.
Determine the amount of bricks needed for the job by multiplying the square footage -- 120 square feet -- by the number of bricks in a square foot -- 4.5. For this instance, 540 bricks are needed. Keep in mind some bricks may be damaged or unusable, so purchase more than necessary for the job. A project such as a patio or walkway may not require mortar between bricks as a wall does. A mortarless installation requires more bricks than a project involving mortar.