Brick Calculator

How Many Bricks a Wall Needs

Brick is counted by wall face area. The number that matters is not the brick size on its own but the brick size plus one mortar joint, because that is the space each brick actually occupies in the finished wall. A modular brick measures 7.625 x 2.25 x 3.625 inches. With the standard 3/8 inch joint, its face takes up 8 inches by 2.625 inches, which is 21 square inches. Divide 144 square inches in a square foot by 21 and the answer is 6.857, normally rounded to about 6.86 bricks per square foot for a single wythe.

A worked example

A single wythe veneer wall 30 feet long and 8 feet high has a face area of 240 square feet. At 6.86 bricks per square foot that is 1,646 bricks. Subtract openings: a 3 ft by 5 ft window is 15 square feet, or about 103 bricks. With one such window the count drops to about 1,543. Add 7 percent for cuts and breakage and the order is roughly 1,651 bricks, which rounds to a convenient pallet quantity with the supplier.

Bricks usually ship on pallets or cubes of 500 or so, though the number varies by manufacturer and by brick size. Ask for the exact cube count before finalizing the order, because paying for a part cube is rarely possible.

Wythes and Wall Thickness

A wythe is one continuous vertical layer of brick, one unit thick. A single wythe of modular brick is 3.625 inches thick, which is a veneer, not a structural wall. A double wythe wall is two layers with a mortar collar joint or an air cavity between them, and it is roughly 8 to 10 inches thick depending on the detail.

For counting, each wythe is a full multiple. A double wythe wall of 240 square feet needs about 3,292 bricks before waste, not 1,646. Headers, which are bricks turned end on to tie two wythes together in a traditional solid wall, change the visible face pattern but not the total unit count in any way worth adjusting for at estimating stage.

Brick Veneer Versus Structural Brick

Almost all modern residential brick in the United States is veneer. The brick carries only its own weight, sits on a brick ledge on the foundation, and is tied back to a wood or steel framed structural wall with corrugated metal ties, typically one tie for every 2.67 square feet of wall.

Three details make a veneer wall work and all three are commonly missed. First, a 1 inch minimum air cavity between the brick and the sheathing, kept clear of mortar droppings. Second, through wall flashing at the base of the wall and over every opening. Third, weep holes at 24 to 33 inches on center in the first course above every flashing, so water that gets into the cavity has somewhere to go. Brick is not waterproof, and a veneer without drainage will move water into the framing.

Structural brick, where the wall carries floor and roof loads, is found in older buildings and in some commercial work. It is thicker, engineered, and not something to estimate from a per square foot figure alone.

Brick Sizes

Brick names are not standardized between manufacturers, and two bricks sold as the same name can differ. Always confirm the actual dimensions on the product data sheet before ordering. Queen size is slightly taller and thinner than modular, and covers more wall per brick, so a queen wall needs about 5.76 bricks per square foot. King size is longer and taller again, at about 4.8 per square foot, which is why it is popular where labor cost dominates.

Mortar

Allow about 7 bags of mortar per 1,000 bricks laid with a standard 3/8 inch joint. The 1,646 brick veneer in the example above therefore needs about 12 bags. That figure covers bed and head joints plus normal waste on the board.

Type N mortar is the usual choice for above grade brick veneer, because it is soft enough to accommodate small movements and to keep cracks in the joint rather than through the brick. Type S is used below grade, at foundations and in high wind or seismic areas. Type O is a low strength mortar reserved for repointing historic soft brick, where a hard modern mortar would destroy the units.

Mix consistency matters more than most estimating figures. A wet, workable mortar wastes more on the board but tools cleanly, and a thin batch that stiffens before it is used should be discarded rather than retempered a second time. Joint thickness also drives the count: a wall built with 1/2 inch joints instead of 3/8 inch needs about 6.4 modular bricks per square foot rather than 6.86, a difference of nearly 7 percent over a large wall.

Waste Allowance

Add 5 to 10 percent to any brick order. Use 5 percent on a plain rectangular wall with few openings and a straightforward bond. Use 10 percent where there are many corners, arched or angled openings, soldier courses, rowlock sills, or a pattern that requires cutting most units along an edge. Rough textured and tumbled bricks break more in handling than smooth wirecut units, so lean toward the higher figure with them.

Keep the leftovers. Brick color comes from clay and firing, and batches vary. A repair made years later with a current production brick will rarely match, so a stored pallet of the original run is the only reliable source of matching units.