The brick calculator above turns a wall size into a brick count, a mortar quantity and a materials cost. It works in imperial or metric, handles the common brick formats used in the United States, the United Kingdom, Europe and Australia, deducts your window and door openings, and gives you both the raw quantity and the rounded-up number you can actually order.
Arb Digital builds free calculators for the arithmetic that sits between a drawing and a delivery note, and bricklaying is a good example of why that arithmetic matters. Bricks are not sold in fractions, and the difference between the theoretical count and the order quantity — cuts, breakages, colour matching — is where projects run short. This page shows both numbers side by side rather than hiding one.
What This Brick Calculator Does
A brick wall is a repeating module. Each brick occupies its own face area plus one mortar joint along the top and one down one side, and that module tiles across the wall. Work out the module area, divide it into the wall area, and you have the brick count. Everything else — bond patterns, openings, waste — is a modification of that basic sum.
The tool covers four standard formats plus a custom option. The US modular brick has a face of 7⅝ by 2¼ inches, which with a ⅜-inch joint tiles into an 8 by 2⅔-inch nominal module. The queen size is the same length but taller at 2¾ inches. The UK and European standard is 215 by 65 millimetres, which with a 10 mm joint gives a 225 by 75 mm module. The Australian standard is 230 by 76 millimetres. The Brick Industry Association's Technical Notes on Brick Construction cover the dimensioning conventions behind these figures, including the distinction between nominal, specified and actual sizes that trips up so many estimates.
Where a live tool sits close by, the boundary matters. Our concrete calculator handles poured concrete volume and bag counts for slabs, footings and columns — a different material with a different unit of sale. This page counts discrete units laid in courses.
How to Use It
- Set your units first. Switching between imperial and metric converts the brick and joint fields, so do it before typing your own dimensions.
- Enter the wall length and height, then the openings. Add up the areas of every window and door and enter the total; the calculator subtracts it from the gross wall area before counting.
- Choose the brick format, or enter a custom face size. Use the specified size — the manufactured size without mortar — not the nominal size, which already includes a joint.
- Set the bond. A single-wythe stretcher-bond wall is one brick thick. English and Flemish bonds are two wythes, so they need roughly twice the bricks for the same face area.
- Set the waste factor and pack size. Ten per cent is the sensible default. If bricks come on pallets of 500, enter 500 and the hero figure rounds up to whole pallets.
The Formula / How It's Calculated
Bricks per unit area is 1 ÷ [(face length + joint) × (face height + joint)]. For a US modular brick with a ⅜-inch joint: (7.625 + 0.375) × (2.25 + 0.375) = 8 × 2.625 = 21 square inches per brick. There are 144 square inches in a square foot, so 144 ÷ 21 = 6.857 bricks per square foot. For a UK brick with a 10 mm joint: 225 × 75 = 16,875 mm², and one square metre is 1,000,000 mm², so 1,000,000 ÷ 16,875 = 59.26 bricks per square metre.
Work the default example. A wall 20 feet long and 8 feet high has a gross area of 160 square feet. Deduct 20 square feet of openings and the net area is 140 square feet. At 6.857 bricks per square foot in single-wythe stretcher bond, that is 959.9, so 960 bricks raw. Add a 10% waste allowance and you get 1,056. That is the number to order, because you cannot buy 959.9 bricks and you certainly cannot buy the half brick that a cut leaves behind.
Mortar is worked out geometrically rather than from a rule of thumb. The mortar occupies whatever fraction of the module the brick face does not: (21 − 17.156) ÷ 21 = 18.3% of the wall face, where 17.156 square inches is 7.625 × 2.25. Multiply that fraction by the wall area and by the bed depth — the brick's width, 3.625 inches — to get the mortar volume. For 140 square feet that comes to about 7.7 cubic feet before waste, or 8.5 with the 10% allowance. Divide by the yield printed on your mortar bag, 0.6 cubic feet being a common figure for an 80 lb bag, and the answer is 15 bags. Always read the yield off the bag you are actually buying rather than trusting a default.
Nominal, Specified and Actual Sizes
Three different dimensions are all called "the brick size", and confusing them is the most common estimating error in masonry. The nominal size is the specified size plus one mortar joint, rounded to a 4 or 8-inch module — it is what you use when laying out a wall against door and window openings. The specified size is the manufactured size without mortar, and it is what appears on the purchase order. The actual size is what came out of the kiln, within the tolerances the relevant standard permits, because fired clay shrinks unevenly.
Enter the specified size in this calculator, because it adds the joint separately. A US modular brick has a specified face of 7⅝ by 2¼ inches and a nominal module of 8 by 2⅔ inches. Enter 8 instead of 7.625 and you will add the joint twice, undercounting the bricks by roughly 5% — which on a thousand-brick job is fifty bricks you did not order.
The actual size matters on site rather than in the estimate. Kiln variation is why bricklayers adjust joint thickness slightly as they go to keep courses level and gauge consistent, and it is why the mortar quantity is always approximate. If your joints run a touch fat, you use more mortar and slightly fewer bricks than any calculator predicts.
Why the Bond Pattern Changes Everything
Bond is the pattern in which bricks overlap, and it determines both the wall's thickness and how many bricks it consumes. Stretcher bond, where every brick shows its long face, produces a single-wythe wall half a brick thick. It is the standard for modern cavity-wall outer leaves and for veneer over a framed structure.
Traditional structural bonds are different animals. English bond alternates courses of stretchers and headers, and Flemish bond alternates stretchers and headers within each course. Both produce a solid wall a full brick thick, which is roughly twice the material for the same visible face area. The bond selector handles this with a straightforward multiplier, which is accurate for the field of the wall.
What the multiplier does not capture is the cutting. Header-bearing bonds need closers — three-quarter bricks at the ends of alternate courses to keep the pattern true — and every closer is a cut from a whole brick. On a wall with many corners, reveals and returns, that pushes real waste above the 10% default. Fifteen per cent is more realistic for a heavily articulated elevation, and the waste field is there so you can say so.
Getting the Waste Factor Right
The waste factor is not padding, and treating it as optional is how jobs stop halfway up a gable. Four separate things consume bricks that the geometry does not account for. Cuts: every opening, corner and rake creates part bricks, and the offcut is usually unusable. Breakage: bricks arrive chipped, get dropped, and crack when cut. Selection: on a face wall the bricklayer discards units with blemishes or off-colour faces. Contingency: a small stock left over covers later repairs with matching brick from the same batch.
Ten per cent covers a straightforward rectangular wall with a couple of openings. Push it to 15% for a wall with many openings, angled cuts, or a decorative bond. Push it further for reclaimed or handmade bricks, where dimensional variation is much greater and the reject rate is higher. Reduce it below 10% only for a long, plain, opening-free run laid by an experienced gang.
The pack-size field handles the other half of the problem. Bricks are usually delivered on packs of a few hundred, and suppliers rarely split them. Rounding your requirement up to whole packs is what you will actually pay for, so the hero figure does exactly that. The same discipline applies to every material on a job — our tile calculator, paint calculator and flooring calculator all round up to purchasable quantities for the same reason.
What This Calculator Deliberately Does Not Do
It counts materials for the field of a wall. It does not design the wall. Structural adequacy, movement joints, wall ties, damp-proof courses, weep holes, lintels over openings, foundation depth and reinforcement are all engineering decisions governed by your local building code, and none of them are quantities you can derive from a length and a height.
It also assumes a rectangular wall. For a gable, a triangular panel, or a wall stepped to follow a slope, work out the area separately and enter it by adjusting the length and height to produce the right net area — or split the job into rectangles and run the calculation more than once. Our wall area calculator handles the geometry side of that, including irregular shapes.
Finally, the cost figures are materials only. They exclude labour, scaffolding, delivery, sand and cement if you are mixing on site rather than using bagged mortar, wall ties, and the plant to move a few tonnes of brick around. Materials are usually the smaller half of a bricklaying bill.
Arb Digital builds free, no-signup calculators for construction, energy, statistics and finance. Browse the full library, or get in touch if there is a calculation your team keeps doing by hand.
Browse All Free Tools Contact Arb DigitalCommon Mistakes to Avoid
- Entering the nominal brick size instead of the specified size — the nominal figure already includes a joint, so you end up adding it twice and undercounting.
- Forgetting that a solid bond is two wythes — English and Flemish bonds need roughly double the bricks of a stretcher-bond wall of the same face area.
- Deducting openings twice — subtract the opening areas once, from the gross wall area, not again from the brick count.
- Ordering in two batches — fired clay colour varies between production runs, and a later top-up can be visibly different in the finished face.
- Using a default mortar bag yield — yields differ between products and mixes, so read the figure off the bag you are buying.
Related Free Tools From Arb Digital
Count masonry units for a block wall with the concrete block calculator, work out poured concrete for the footing with the concrete calculator, measure irregular elevations with the wall area calculator, and convert bulk material volumes with the cubic yard calculator. For finishes, the paint calculator and tile calculator follow the same round-up logic. NIST's guidance on unit conversion is a reliable reference if you are working across imperial and metric drawings. The full free online tools hub holds the rest of the construction set.
Frequently Asked Questions
For a US modular brick with a ⅜-inch mortar joint, about 6.86 bricks per square foot of single-wythe wall face. The module is 8 by 2.625 inches, which is 21 square inches, and 144 divided by 21 gives 6.857.
For a UK or European standard brick of 215 by 65 mm with a 10 mm joint, about 59.3 per square metre, usually quoted as 60. The module is 225 by 75 mm, which is 16,875 square millimetres, and a square metre holds 59.26 of them.
Ten per cent suits a straightforward rectangular wall. Raise it to 15% where there are many openings, corners, angled cuts or a decorative bond, and higher again for reclaimed or handmade bricks where dimensional variation and rejects are greater.
The raw figure is the geometric requirement. The order figure adds your waste allowance and rounds up to whole bricks or whole packs, because suppliers do not sell fractions and rarely split pallets. The order figure is what you buy.
It depends on the joint thickness and the brick bed depth. This tool derives the mortar volume from the fraction of the wall face the joints occupy, multiplied by the brick width, then divides by the yield printed on your mortar bag rather than assuming a fixed figure.
The specified size is the manufactured size of the brick itself. The nominal size is that plus one mortar joint, rounded to a 4 or 8-inch module for layout purposes. Enter the specified size here, because the calculator adds the joint separately.
Approximately yes for the field of the wall. English and Flemish bonds produce a solid wall a full brick thick, so the material is roughly double a stretcher-bond wall of the same face area, plus extra cutting for the closers those bonds require.
No. It counts materials only. Foundations, lintels, wall ties, damp-proof courses and movement joints are code-governed engineering decisions that need a qualified designer.
This calculator is provided for education and planning only. Quantities are estimates and exclude labour, scaffolding and delivery. Structural design, foundations and compliance with your local building code should be confirmed by a qualified engineer or builder before you order or build.
