How many bricks per square foot
There is no single answer, and the widely repeated “about 7 bricks per square foot” is only true for two of the sizes below. The rate is set by the brick's face — its height and length — plus the mortar joint around it. Here is what BIA publishes, expressed per square foot:
| Size | Face (H × L) | Per ft² | Per 100 ft² |
|---|---|---|---|
| Modular | 2⅔ × 8 nom. | 6.75 | 675 |
| Engineer Modular | 3⅕ × 8 nom. | 5.63 | 563 |
| Closure Modular | 4 × 8 nom. | 4.50 | 450 |
| Roman | 2 × 12 nom. | 6.00 | 600 |
| Norman | 2⅔ × 12 nom. | 4.50 | 450 |
| Utility | 4 × 12 nom. | 3.00 | 300 |
| Meridian | 4 × 16 nom. | 2.25 | 225 |
| Standard * | 2¼ × 8 spec. | 6.55 | 655 |
| Queen * | 2¾ × 8 spec. | 5.50 | 550 |
| King * | 2¾ × 9¾ spec. | 4.55 | 455 |
* Non-modular — see the joint warning below.
The practical consequence is that brick size drives cost more than most people expect. A wall in Meridian takes 225 units per 100 ft² where the same wall in modular takes 675 — a third as many pieces to buy, handle and lay. That is why larger units show up on commercial work and why king size took over so much production housing. The brick sizes chart has the full dimensions, coursing and mortar figures behind every row here.
Modular vs non-modular: the joint trap
This is the single most common error in brick estimating, and it is worth understanding before you trust any calculator, including this one.
A modular brick is sized so that its specified dimension plus the intended mortar joint equals a round number. Modular brick is 4 × 2⅔ × 8 in. nominal, and its actual manufactured size is 3⅝ × 2¼ × 7⅝ — the missing ⅜ in. is the joint. So when you calculate coverage from the nominal size you must add nothing, because the joint is already in there.
A non-modular brick — standard, queen, king — has no nominal size at all. Its published dimensions are the brick itself, so the joint has to be added on top. Standard brick is 3⅝ × 2¼ × 8; with a ⅜ in. joint each one occupies 2⅝ × 8⅜ in. of wall.
Get that rule backwards on a standard brick and you overstate the count by about 15%. Both sizes are “8 inches long” in casual conversation, which is exactly why the mistake is so easy to make: modular is 8 in. nominal, standard is 8 in. specified.
There is a subtler trap on top of it. BIA publishes one brick count per size, and for the non-modular sizes that count sits on a ⅜ in. joint. Lay standard brick with a ½ in. joint and the honest figure is 6.16 per square foot, not the published 6.55 — taking the table at face value over-orders by about 6%. This calculator uses the published figure where it agrees with the geometry and falls back to the geometry where it does not, and the working panel tells you which one it used and why.
Mortar, and why its waste factor is not the brick's
Most calculators apply one waste percentage to the whole job. BIA does not, and the reason is physical: brick and mortar are lost in completely different ways.
Brick breaks. That is essentially the whole failure mode, and BIA's guidance is that “at least 5 percent is added to the net brick quantities.” Mortar, on the other hand, is dropped off the trowel, scraped off boards, squeezed out of joints and struck away, and goes off in the tub if a batch outlives its working time. BIA's allowance for it is 15 to 25 percent — three to five times the brick figure.
The two fields above are therefore separate, and both default to BIA's numbers. Note also that the 5% is described as a floor rather than a typical value: the source says “particular job conditions or experience may warrant using a higher percentage”. Cut work, tight radii and reclaimed brick all push it up.
Mortar quantities themselves scale with joint area, not brick count, so bigger units need more mortar per thousand — 8.1 ft³ per 1000 modular against 12.3 ft³ per 1000 utility at the same ⅜ in. joint. Going from a ⅜ to a ½ in. joint raises mortar by roughly a quarter across every size in the table.
Bond pattern changes the count
BIA's quantity tables assume running or stack bond — every brick laid as a stretcher, face out. Any pattern that turns brick sideways into the wall as headers uses more units for the same visible area, because a header shows only its end.
The corrections are real money on a large wall. Common bond with full headers every fifth course adds a fifth to the brick count. English bond, with headers every second course, adds half again. Mortar rises too but proportionally less, since headers displace joint area as well as adding it. The selector above applies BIA's Table 6 factor to brick and mortar separately, before waste — which is the order BIA specifies, and it matters: correction first, waste last.
Ordering: pallets, cubes and partial units
The number this tool gives you is a quantity of brick, not a purchase order. Brick is sold in banded cubes or pallets whose count varies by manufacturer and size — commonly a few hundred units — so your real order rounds up to whole cubes. Ask your supplier what their cube count is for the size you are buying before you order, because rounding up two cubes on a small job is a meaningful overspend and rounding down leaves you short at the worst moment.
Colour is the other reason to order the whole job at once. Brick is a fired clay product and batches vary; a top-up order weeks later can arrive visibly different. That is a stronger argument for a healthy waste allowance than breakage is.
What this tool will not do
It does not design the wall. Wythe count, ties, weeps, flashing, lintels, expansion joints and foundation support are engineering and code questions, and a brick veneer is a very different assembly from a structural brick wall even though both take the same face quantity. This calculator counts units and mortar for a face area you give it.
It also does not estimate mortar ingredients. The output is cubic feet of mixed mortar; how that converts to bags of masonry cement, sand and lime depends on the mortar type and mix proportions you are specifying. The mason's 8-bags-per-1000-modular rule of thumb is in the FAQ, but BIA itself calls that figure “very rough”, and it quietly includes an unspecified amount of waste — so do not stack your own waste allowance on top of it.