How Many Bricks Per Square Foot?

The brick you order is not the brick you lay. The mortar joint counts as part of the face, and that changes the count on every square foot of the wall.

ConstructionBy Aug 21, 20266 min read
How Many Bricks Per Square Foot? — ListCalc

The joint is part of the brick

A standard US modular brick has a face of 7 5/8 by 2 1/4 inches. If you tried to work out coverage from those numbers you would get the wrong answer, because a brick is never laid on its own — it comes with a mortar joint attached.

Add the usual 3/8 inch joint to each dimension and the effective footprint becomes 8 by 2 5/8 inches, which is 21 square inches. There are 144 square inches in a square foot, so:

144 ÷ 21 = 6.86 bricks per square foot

That figure is why the standard sizes look the way they do. Three courses of modular brick, joints included, come to exactly 8 inches of height, which lines up with the block and the window openings around it.

What ignoring the joint costs you

Run the same calculation without the mortar and the face is 17.16 square inches, giving 8.39 bricks per square foot. That is 22% higher. On a 160 ft² wall it is the difference between ordering 1,097 bricks and ordering 1,343 — roughly 250 spare bricks you did not need and cannot return once the pallet is broken.

A worked wall

Take a wall 20 ft long and 8 ft high, with no openings. That is 160 ft².

At 6.86 per ft², you need 1,097 bricks to cover it.

Add the standard 10% for breakage and cuts and the order becomes 1,207 bricks.

Mortar for that runs to about nine 70 lb bags, plus sand if you are mixing rather than buying it premixed.

Two wythes doubles the brick, not the area

A double-wythe wall is two leaves of brick thick. The wall area does not change, but you are laying two bricks for every one on the face, so the count doubles. Solid masonry walls in older construction are often two or even three wythes.

Order in one go

Brick colour comes from the clay and the kiln, and both drift between firings. Product codes do not guarantee a match across batches. If you run short and reorder a month later, the new brick can land noticeably lighter or darker in a wall that is already up. Ordering the whole job, waste included, in a single delivery is the only reliable way to avoid it.

Run your own numbers

Brick Area Concrete

FAQ

How many bricks are in a square foot?
For a standard modular brick with a 3/8 inch mortar joint, 6.86 per square foot for a single-wythe wall. The face measures 7 5/8 by 2 1/4 inches, and adding the joint makes the effective footprint 8 by 2 5/8 inches, which is 21 square inches. 144 ÷ 21 = 6.86.
Does the mortar joint really change the count?
Substantially. Without the joint you would fit 8.4 bricks per square foot instead of 6.86 — about 22% more. Any count that ignores the joint will have you ordering far too many.
How much waste should I add to a brick order?
10% is normal, covering breakage, cuts at openings and the corner bricks that get trimmed. Add more for a wall with many windows or angled work.
How much mortar do I need per thousand bricks?
Roughly 7 to 8 bags of 70 lb mortar mix per thousand modular bricks with a 3/8 inch joint, plus sand if you are mixing from scratch rather than buying premixed.
Why should I order all the brick at once?
Colour varies between firings. Two batches of the same product number, ordered weeks apart, can be visibly different in the same wall, and there is no fixing it after the fact.

Sources

Primary references used for the figures and rules on this page.

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