Header courses need extra brick.
Wall 1
Windows and doors to deduct.
For weep hole spacing.
Advanced options
12–15% for decorative bonds or curves.
This brick calculator uses real modular coursing rather than a rounded rule of thumb, adds the header bricks that decorative bonds actually need, and gives mortar as a range — because the published figures for it differ by a factor of four.
The short answer
Modular brick at a ⅜ in joint is 6.75 per square foot. A 20 × 8 ft wall is 160 ft², so 1,080 bricks — call it 1,188 with 10% waste.
Mortar for that wall is 17 to 33 bags depending on whose figure you use. Both ends of that range are defensible, and the widely-quoted “7 bags per 1,000 bricks” is not.
On this page
How to use this brick calculator
Pick a brick size, joint width and bond pattern, then enter the wall. Three modes:
- Single wall — length, height and openings to deduct
- Whole building — perimeter dimensions and wall height
- Known area — plus the base course length, for weep spacing
The header toggle sets wall thickness: veneer (one wythe, the normal case for a modern house) or two and three wythes for structural masonry.
Bond pattern matters more than most people expect, so it’s on the main panel rather than buried in advanced options.
Is modular brick 6.75 or 6.86 per square foot?
Both figures are published, both cite authority, and they disagree by 1.6%. It’s worth understanding which to use, because the reason is genuinely interesting.
The formula gives 6.86. A modular brick is specified at 7⅝ × 2¼ in. Add a ⅜ in joint to each dimension and you get 8 × 2.625 in, so 144 ÷ 21 = 6.86 per ft².
The BIA gives 6.75, and the difference is in the course height. Modular brick isn’t sized arbitrarily — it’s designed so that three courses make exactly 8 inches, letting brickwork align with other modular materials. That makes the true course height 8 ÷ 3 = 2.667 in, not 2.625. So 144 ÷ (8 × 2.667) = 6.75.
That’s the resolution. To make three courses land on 8 inches with a 2¼ in brick, the bed joint has to average 0.417 in — slightly fatter than the nominal ⅜. Masons hit this naturally by working to a course rod rather than measuring each joint.
So use 6.75 for modular brick at a standard joint, which is what BIA TN 10 Table 4 publishes and what suppliers quote. Use the formula for non-modular sizes and non-standard joints, where no coursing rule applies. This calculator switches between the two automatically.
Brick sizes
Coverage at a ⅜ in joint, using modular coursing where the size has one.
| Size | Face (L × H) | Per ft² | Notes |
|---|---|---|---|
| Modular | 7⅝ × 2¼ in | 6.75 | US standard, 3 courses = 8 in |
| Standard | 8 × 2¼ in | 6.55 | Slightly longer, no coursing rule |
| Queen | 7⅝ × 2¾ in | 5.76 | Taller, fewer courses, cheaper to lay |
| King | 9⅝ × 2⅝ in | 4.80 | Larger face, popular for cost |
| Norman | 11⅝ × 2¼ in | 4.50 | Long and low, modern look |
| Roman | 11⅝ × 1⅝ in | 6.00 | Very slim, strongly horizontal |
| Utility | 11⅝ × 3⅝ in | 3.00 | Large format, fastest to lay |
| UK metric | 215 × 65 mm | 5.55 | Use a 10 mm joint |
Modular needs 6.75 per ft²; queen needs 5.76; king needs 4.80. Order modular quantities and lay king brick and you’ll have 40% too many. The reverse leaves you badly short.
“Standard” and “modular” sound interchangeable and aren’t — the standard brick is ⅜ in longer, which is a 3% difference on its own. Confirm the size against your supplier’s spec sheet, not against a general chart.
Joint width
| Joint | Modular per ft² | Change | Use |
|---|---|---|---|
| ¼ in | 7.31 | +8% | Tight, precise work |
| ⅜ in | 6.75 | — | US standard |
| ½ in | 6.44 | −5% | Rustic, hand-made brick |
Joint width works in opposite directions on the two orders: a fatter joint means fewer bricks but more mortar. The calculator scales both.
Joint profile — how you tool it after striking — doesn’t change quantity but does change performance. A concave or “bucket handle” joint compacts mortar against the brick edges and leaves no ledge for water to sit on. Raked and struck joints look good and shed water badly.
Bond patterns need more brick
This is the input most calculators leave out entirely, and it can add half again to your order.
A header is a brick turned end-on so its short face shows. Header courses tie multiple wythes together, and in decorative bonds they appear for looks. Because a header shows only its width rather than its length, it covers far less wall — so you need more bricks per square foot.
| Bond | Extra brick | On a 1,080-brick wall | Pattern |
|---|---|---|---|
| Running | — | 1,080 | All stretchers, offset half a brick |
| Stack | — | 1,080 | All stretchers, aligned. Needs reinforcement |
| Common | +17% | 1,260 | Header course every sixth course |
| Flemish | +33% | 1,440 | Stretcher and header alternating in every course |
| English | +50% | 1,620 | Alternate courses entirely stretchers or headers |
English bond needs 540 more bricks than running bond on the same 160 ft² wall. Decorative bonds also generate far more cutting, so push the waste allowance to 12–15% rather than the usual 10%.
The mortar problem
Published figures for mortar per 1,000 bricks include 7 bags, 14 bags, 27 bags and 35–40 bags. That is not a modest disagreement, and it’s worth being precise about which are real.
| Figure | Per 1,000 | Where it comes from |
|---|---|---|
| Engineering | 14 bags | BIA net volume of 8.1 ft³, plus 25% field waste, ÷ 0.75 ft³ per 80 lb bag |
| Manufacturer | 27 bags | 37 bricks per 80 lb bag from the bag data sheet — heavy waste already included |
| 70 lb bags | 35–40 | The same as 27 at 80 lb, restated for a smaller bag |
| 7 bags | — | Wrong. See below |
Seven 80 lb bags yield 5.25 ft³ of mortar. Laying 1,000 modular bricks needs 8.1 ft³ net per the BIA — so that figure is 1.5× short before a single trowelful hits the ground, and roughly 4× short against the manufacturer’s own working figure.
Anyone following it stops work halfway through a wall, which with mortar is worse than it sounds — a cold joint in the middle of a lift is a permanent weakness, not just an inconvenience.
The genuine range is 14 to 27 bags per 1,000. Order toward the lower end if you’re experienced and measuring carefully, and toward the upper end if this is your first wall — beginners drop and over-butter a lot of mortar. The calculator shows both.
Wythes
| Wall | Thickness | Where used |
|---|---|---|
| Single wythe (veneer) | ~4½ in | Modern houses. Non-structural, hung on a framed wall |
| Two wythe | ~9 in | Pre-1960 solid walls, garden walls, chimneys |
| Three wythe | ~13 in | Older structural masonry, retaining work |
Brick count multiplies directly by the wythe count. Mortar increases by more than that, because each additional wythe adds a collar joint — the vertical mortar layer between wythes — which the face-area figures don’t include. Add roughly 10% to mortar per collar joint.
Anything above one wythe is structural. It needs a proper foundation, ties or header courses bonding the wythes together, and in most cases an engineer.
Ties and weep holes
This surprises people: a brick veneer wall is expected to let water through. Brick and mortar are both porous, and wind-driven rain gets past regardless of workmanship.
What keeps the building dry is the cavity behind the brick, the flashing at its base, and the weep holes that let water back out. Block those and you haven’t built a waterproof wall — you’ve built a wall that holds water against the framing.
| Item | Requirement | Reference |
|---|---|---|
| Wall ties | 1 per 2.67 ft² | IRC R703.8 |
| Tie spacing | 24 in horizontal, 16 in vertical max | IRC R703.8 |
| Weep holes | 33 in apart maximum | IRC R703.8.6 |
| Air space behind brick | 1 in minimum | IRC R703.8.4 |
The classic failure is mortar droppings filling the cavity base and blocking the weeps from behind. Keep the cavity clear as you lay — once the wall is up there is no way to clean it out.
The formula
Bricks per ft² = 144 ÷ [(Length + joint) × Course height]
Bricks = Net area × per ft² × (1 + bond extra) × wythes × (1 + waste)
Course height is 8 ÷ 3 for modular brick at a ⅜ in joint,
otherwise brick height + joint
Worked example — 20 × 8 ft veneer wall, modular brick, running bond
Brick estimating mistakes to avoid
- Using 7 bricks per ft² for everything. It’s 6.75 for modular and 4.80 for king.
- Ignoring the bond pattern. English bond needs 50% more brick than running.
- Trusting “7 bags of mortar per 1,000”. The real figure is 14 to 27.
- Confusing standard with modular. Different lengths, different counts.
- Forgetting the collar joint on multi-wythe walls. Add 10% mortar per joint.
- Ordering short and topping up later. Brick colour varies between firings.
- Letting mortar drop into the cavity. It blocks the weeps and traps water.
- Treating veneer as waterproof. It’s a drainage system; the flashing does the work.
Frequently asked questions
How many bricks per square foot?
6.75 for modular brick at a ⅜ in joint, which is the BIA figure suppliers quote. Queen is 5.76, king 4.80, Norman 4.50 and utility 3.00. The count depends on the brick’s face dimensions plus the joint, so confirm your actual size before ordering.
Why do sources say 6.75 and others 6.86?
Different course heights. The raw formula adds ⅜ in to the 2¼ in brick height for 2.625 in, giving 6.86. But modular brick is designed so three courses make exactly 8 inches, making the real course height 2.667 in and the count 6.75. The BIA publishes 6.75, and that’s what to use for modular at a standard joint.
How much mortar do I need per 1,000 bricks?
Between 14 and 27 bags of 80 lb mortar. 14 is the engineering figure — 8.1 ft³ net per the BIA plus 25% field waste. 27 comes from the manufacturer’s 37 bricks per bag, which assumes heavier waste. The widely-quoted 7 bags is wrong: it yields 5.25 ft³ against a net requirement of 8.1.
Does the bond pattern change how many bricks I need?
Substantially. Header courses show the brick’s short face, so they cover less wall. Per BIA TN 10 Table 6, common bond needs 17% more brick than running bond, Flemish 33% more and English 50% more. On a 1,080-brick wall that’s up to 540 extra bricks.
How does mortar joint width affect the count?
A wider joint means fewer bricks but more mortar. Modular brick goes from 7.31 per ft² at a ¼ in joint to 6.75 at ⅜ in and 6.44 at ½ in. Both orders change in opposite directions, so adjust each.
What is a wythe?
One continuous vertical thickness of brick. Single-wythe veneer is about 4½ in thick and is the norm on modern houses — non-structural, hung on a framed wall behind. Two and three wythe walls are structural masonry. Brick count multiplies by the wythe count, and mortar increases further for the collar joints between them.
How many wall ties do I need?
One per 2.67 ft² of wall under IRC R703.8, spaced no more than 24 in horizontally and 16 in vertically. A 160 ft² wall needs about 60 ties. They hold the veneer to the structure — the veneer carries no load itself but must not fall off.
Why does brick veneer need weep holes?
Because brick veneer is a drainage wall, not a waterproof one. Water gets through brick and mortar in wind-driven rain, and the cavity, flashing and weep holes route it back out. The IRC requires weeps no more than 33 in apart along the base course. Mortar droppings blocking the cavity is the classic failure.
How much waste should I allow for brick?
10% for straightforward running bond work. Raise it to 12–15% for decorative bonds, walls with many openings, or curved work, since all three generate more cutting. Order the whole job at once — brick colour varies between firings and cannot be blended later.
What is the difference between modular and standard brick?
Length. Modular is 7⅝ in and standard is 8 in, both 2¼ in high. Modular is designed around the 8 in module so three courses make 8 inches; standard has no coursing rule. That gives 6.75 per ft² against 6.55 — a 3% difference, and the names are easy to confuse.
How many bricks are on a pallet?
Typically 500 for modular and standard brick, and around 450 for queen and king. Larger utility brick runs nearer 400. Suppliers call these cubes, and counts vary by manufacturer, so confirm before ordering — it affects delivery and handling more than price.
Can I use this brick calculator in metric?
Yes — select UK metric brick (215 × 65 mm) with a 10 mm joint, which gives 5.55 per ft². For fully metric working, multiply square feet by 0.0929 for square metres, so 5.55 per ft² is about 59.7 bricks per square metre.
Standards and sources
- BIA Technical Note 10 Table 4 — brick coverage per square foot by size and joint width
- BIA Technical Note 10 Table 6 — additional brick required for header courses in bonded patterns
- BIA net mortar volume of 8.1 ft³ per 1,000 modular brick, single wythe at a ⅜ in joint
- IRC R703.8 — anchored masonry veneer: tie spacing, air space and weep hole requirements
- ASTM C216 for facing brick and C270 for mortar
- Coverage figures cross-checked against the face-dimension formula for all eight sizes; published values of 6.86, 5.76 and 4.80 all reproduce exactly
Related calculators
How this brick calculator works out its numbers
Coverage is 144 divided by the installed module — the brick’s specified length plus one joint, times the course height. Course height uses the BIA modular value where the brick has one and the joint is the standard ⅜ in, and falls back to brick height plus joint otherwise. That switch is why modular brick reports 6.75 at a standard joint but a formula-derived figure at any other.
Bond patterns apply the BIA TN 10 Table 6 header allowance to the face count. Wythes multiply it. Waste is applied last, so it covers the whole order rather than just the face course.
Mortar starts from the BIA net volume of 8.1 ft³ per 1,000 bricks, scaled linearly by joint width against the ⅜ in baseline. Two figures are then reported: an engineering number adding 25% field waste and dividing by bag yield, and a manufacturer number from bricks per bag. Both are shown because the honest answer is a range.
These are quantities, not a structural design. Veneer above two storeys, multi-wythe structural walls, retaining work and anything carrying load need an engineer. Coverage and mortar figures are estimating references — confirm against your supplier’s spec sheet and the bag’s own data, both of which take precedence over any general chart including this one.