Why the joint is the whole calculation
A brick wall is brick and mortar together, and the unit that divides into
the wall is the space one brick occupies once its joint is added — not the
brick you can hold in your hand.
face = (brick length + joint) × (brick height + joint)
= (7.625 + 0.375) × (2.25 + 0.375)
= 8 × 2.625 in = 0.1458 ft²
bricks per ft² = 675 ÷ 100 = 6.75 (published, not derived)
Count by the bare brick instead and you get 7.87 per square foot. On a
1,000 brick job that is a pallet too many — bought, delivered and stacked
in the garden for a decade.
Common mistakes
- Counting by the brick, not the module. Worth about a sixth of the order.
- Assuming all bricks are modular. Queen, king and utility all cover differently.
- Ordering exactly. Colour varies between firings; spares have to come from the same batch.
- Forgetting this is one wythe. A double-thickness wall is twice this count.
What goes behind and below
Brick veneer usually sits over a block backing, which the
concrete block
calculator works out including its own mortar. Whatever the wall is
made of, it stands on a footing — the
concrete calculator sizes that
and gives the bag count.
Bricks and mortar by wall size
Computed by this page's own calculator at zero waste — add five to ten percent for cuts, breakage and matching spares.
The rest of the build
Brickwork rarely stands alone. The
retaining wall calculator
covers a wall holding ground back rather than enclosing space, the
post hole calculator works
out the concrete around any post set alongside it, and the
fence calculator handles the
run that carries on where the wall stops. For an elevation that is not a
plain rectangle, the
square footage calculator
adds and subtracts areas and hands the total over.
A correction to this page
This calculator originally figured mortar at seven 80 lb bags per
thousand bricks, which is what a widely circulated estimating table says.
QUIKRETE publish a yield for their own mortar mix — 37 standard bricks or
13 blocks to an 80 lb bag — and that works out at nearly four times
as much. The published figure is the one now used, so a thousand bricks
that read as seven bags now reads as twenty-eight. If you ordered from an
earlier version of this page, that is the difference.
The brick count itself did not change, and deliberately does not move
with joint width: modular brick is manufactured smaller for a wider
joint, so the Brick Industry Association's 675 per 100 ft² holds at
3/8 in and at 1/2 in. The mortar between them is what changes.
Common questions
Can I mix my own mortar instead of buying bags?
Yes, and the calculator gives you the proportions. Pick type N or type S above and it works out how much cement, lime and sand the wall takes, using the proportion specification in ASTM C270 — one part portland cement to a band of lime, with sand at two and a quarter to three times the total cementitious volume. Both ends of that band are shown because both are recipes the standard permits and the truth sits between them; combining the low end of one with the high end of the other would give a spread of nearly four to one on the sand, which is not an answer. The figures are dry volumes and they pack down when mixed, so buy a little over.
Does the calculator handle Norman, Roman or utility brick?
Yes — nine sizes, all from the Quantity Estimates table in the Brick Industry Association’s Technical Note 10. Pick yours above and both the brick count and the mortar follow it. The differences are large enough to matter: a modular wall takes 675 brick per hundred square feet and a Norman takes 450, so ordering modular quantities for a Norman wall buys half again what you need. The mortar moves too, and not in step with the count — a Norman wall has fewer joints but longer ones.
How many bricks do I need per square foot?
Exactly 6.75, which is the figure the Brick Industry Association publishes: 675 brick per 100 square feet of wall. It is not derived, and it is worth knowing why. Modular brick is built to a 4 by 2-2/3 by 8 inch module that already contains the joint, so the count per square foot is fixed by the module and does not change when the joint does — a wider joint is met by a smaller brick. Adding a 3/8 inch joint to the bare brick face gives 6.86, which is close but is not the published number.
Why does the joint change the brick count?
Because you are covering the wall with brick plus mortar, not with brick. Count by the bare 7 5/8 by 2 1/4 inch brick and you get 7.87 per square foot instead of the published 6.75 — about a sixth too many, which on a thousand-brick job is a pallet you did not need.
How much mortar do I need per 1,000 bricks?
About 27 bags of 80 lb, working from the yield the mortar manufacturer publishes: one 80 lb bag of Mason Mix lays up to 37 standard bricks. That is a lot more mortar than the rules of thumb that circulate — this page used to quote seven bags of 70 lb per thousand, which is roughly a quarter of what any published source supports and would have left you standing at the merchant on day two. Where you land still depends on how full your beds are and how the joints are tooled.
What size is a modular brick?
7 5/8 by 2 1/4 by 3 5/8 inches. That is the actual brick; the nominal size — the one the coursing is designed around — is 8 by 2 2/3 by 4, and the difference is the joint. Queen, king and utility bricks are all different sizes and cover different areas, so check what your supplier is quoting before using any per-square-foot figure.
Should I add waste?
Five to ten percent. Bricks arrive chipped, some get cut for the bond at corners and openings, and you want spares in the same batch — brick colour varies noticeably between firings, so a replacement pallet ordered later rarely matches what is already on the wall.
Does this cover a double-thickness wall?
No. This counts the face area, so it gives you one wythe — a single thickness of brick. A double wythe wall, or a brick veneer over block, needs the count doubled or the backing calculated separately with the concrete block calculator.
