Materials & quantities
Brick & block quantity calculator
Estimate masonry units from wall area, openings, joints and waste.
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What a brick and block calculator does
A brick calculator estimates how many bricks or concrete blocks a wall needs from its area and the size of one unit plus its mortar joint. Standard modular brick laid with 3/8 in joints works out at 6.75 bricks per square foot, and 8 × 8 × 16 in concrete masonry units (CMU) at 1.125 blocks per square foot.
The method is the one estimators use for a quick takeoff. Subtract openings from the wall area, work out the face area of one unit including its joint (its nominal module), and divide. A 16 × 8 in block module is 128 in², or 0.889 ft², so 240 ft² of wall needs 270 blocks before waste.
The calculator does this for any unit size in inches or millimetres, adds a waste allowance, draws the wall face and can price the order. It counts a single wythe (leaf). A double-wythe wall, or a veneer plus a block backup, needs each leaf counted separately.
How to use the brick & block quantity calculator
- Choose Imperial or Metric. Wall dimensions are entered in feet or metres; unit sizes and the joint in inches or millimetres.
- Enter the wall Length and Height, and the Total opening area of the doors and windows to deduct.
- Pick a Unit preset: US modular brick, US 8 × 8 × 16 CMU (the default, 15.625 × 7.625 in with a 0.375 in joint), UK standard brick, AU standard brick, NZ 70-series brick or AU/NZ 20-series block. Each sets the face size, joint and mortar bed. Choose Custom to enter the actual Unit length and Unit height without mortar, as decimals (7.625 for 7-5/8 in), the Mortar joint and the Mortar bed depth.
- Enter any Shared corners / piers and the Units deducted per corner / pier (about one unit per course; the result shows the course count), then the Mortar yield per bag from the mortar label.
- Set a Waste allowance and, if you want a cost, an optional price per unit.
- Read the net wall area, courses, units before waste, units to order, mortar volume and mortar bags. Download the wall diagram as SVG, export a PDF or CSV, or copy the result.
Worked example
Imperial: A 240 ft² wall using a 16 × 8 in nominal block module needs 270 blocks before waste.
Metric: A 10 m² wall using a 400 × 200 mm nominal block module needs 125 blocks before waste.
How many bricks per square foot?
Divide 144 by the nominal face area of one unit in square inches. The nominal size is the actual size plus one mortar joint in each direction. Modular brick is designed so that three courses, including joints, measure 8 in, which gives a nominal face of 8 × 2-2/3 in and 6.75 bricks per square foot.
To reproduce the 6.75 figure in the calculator, enter a unit height of 2.29 in (the 2-2/3 in course less the 3/8 in joint). Entering the 2-1/4 in actual height with a 3/8 in joint gives a 2-5/8 in course and 6.86 bricks per square foot, a slightly more conservative count.
Concrete blocks with the same 8 × 16 in face (6, 8, 10 and 12 in wide units) all come out at 1.125 per square foot, because width does not change the face area. Brick sizes below follow the Brick Industry Association's modular dimensions; actual sizes vary between plants, so confirm them with your supplier.
| Unit | Actual size (in) | Nominal face (in) | Units per ft² | Units per 100 ft² |
|---|---|---|---|---|
| Modular brick | 3-5/8 × 2-1/4 × 7-5/8 | 8 × 2-2/3 | 6.75 | 675 |
| Engineer modular brick | 3-5/8 × 2-13/16 × 7-5/8 | 8 × 3-1/5 | 5.63 | 563 |
| Utility brick | 3-5/8 × 3-5/8 × 11-5/8 | 12 × 4 | 3.00 | 300 |
| 8 × 4 × 16 half-high CMU | 7-5/8 × 3-5/8 × 15-5/8 | 16 × 4 | 2.25 | 225 |
| 8 × 8 × 16 CMU | 7-5/8 × 7-5/8 × 15-5/8 | 16 × 8 | 1.125 | 112.5 |
How many bricks per square metre?
The same method works in millimetres. A UK standard brick is 215 × 102.5 × 65 mm. With 10 mm joints its face module is 225 × 75 mm, so a half-brick (single-leaf) wall takes 59.3 bricks per square metre, usually rounded to 60. A one-brick-thick wall uses two leaves, about 119 per square metre.
| Unit | Face size (mm) | Module with joint (mm) | Units per m² |
|---|---|---|---|
| UK standard brick | 215 × 65 | 225 × 75 | 59.3 |
| 440 × 215 mm block | 440 × 215 | 450 × 225 | 9.88 |
| 390 × 190 mm block | 390 × 190 | 400 × 200 | 12.5 |
Worked example: brick veneer on a house front
A 36 × 9 ft front wall has two 3 × 5 ft windows and a 3 × 7 ft door. The gross area is 324 ft², the openings total 51 ft², and the net area is 273 ft².
With modular brick entered as 7.625 × 2.29 in and a 0.375 in joint, the calculator gives 1,844 bricks before waste. At 5% waste that becomes 1,937, and at 10% it becomes 2,029. Bricks are sold by the piece, pack or pallet, and pack counts vary, so round up to the supplier's unit.
For a block wall, a 24 × 10 ft garage wall with no openings is 240 ft², which is 270 standard 8 × 8 × 16 blocks, or 284 with 5% waste.
| Waste allowance | Bricks to order |
|---|---|
| 0% | 1,844 |
| 5% | 1,937 |
| 10% | 2,029 |
What a wall-area brick estimate leaves out
An area count is the right starting point for a takeoff, but it does not see the details that consume extra units or need different ones. Allow for these separately.
- Bond pattern: running bond veneer matches the area count, but bonds with headers (such as Flemish or English bond in solid walls) use more units per square foot of face.
- Specials and features: soldier courses, rowlocks, sills, bullnose corners and lintels.
- CMU specials: half blocks, corner blocks, lintel and bond-beam blocks.
- Gable ends: a triangle is half the area of its bounding rectangle. Enter the gable at half its peak height.
- Ties, reinforcement and grout fill: not calculated here. Mortar is estimated from the geometric joint volume and your bag yield; hollow block presets assume face-shell bedding.
Who it is for and when to use it
Masonry takeoffs for bids
Run each elevation with its openings to get a unit count and cost per wall, then export the results to CSV for the estimate.
Brick veneer on renovations and extensions
Size a new veneer or match an existing one on an addition, entering the actual dimensions of the brick you are matching.
Garden walls and block partitions
Count blocks for a non-structural garden wall, planter or garage partition. Retaining and structural walls need engineering beyond this count.
Comparing unit sizes
See how many fewer units a larger brick needs for the same wall. Utility brick needs 300 per 100 ft² against 675 for modular.
Method, formulas & assumptions
Net wall area = length × height − openings. Module area = (unit length + joint) × (unit height + joint) from the preset or your custom unit. Quantity = ceil((net area ÷ module area − corners × units each) × waste factor). Mortar = bed depth × (module area − unit face) per unit, divided by the bag yield.
Imperial inputs are converted with exact factors (1 ft = 0.3048 m, 1 lb = 0.45359237 kg, 1 US gal = 3.785411784 L) before the calculation runs in SI, then results are converted back.
Common mistakes to avoid
- Dividing by the actual unit face instead of the nominal one. Using 7-5/8 × 2-1/4 in without the joint gives 8.39 modular bricks per square foot, a 24% overcount.
- Forgetting that the count is per wythe. A double-wythe wall needs twice the units.
- Using the metric 390 × 190 mm default on an imperial job. It is close to, but not the same as, a 15-5/8 × 7-5/8 in block.
- Ordering to the exact count. Broken units, cuts at openings and corners, and color matching all need a margin.
- Buying brick in several small orders. Color varies between production runs, so order the whole job at once and blend from several packs as you lay.
- Deducting openings without adding the sills, lintels and soldier courses around them.
Scope & limits
A single-leaf area estimate with a simple corner/pier deduction. Mortar is geometric joint volume. Bond, specials, lintels, ties, grout fill and structural design are outside this estimate.
Frequently asked questions
How many bricks per square foot?
Modular brick with 3/8 in mortar joints needs 6.75 bricks per square foot, or 675 per 100 square feet of single-wythe wall.
How many concrete blocks per square foot?
Standard blocks with an 8 × 16 in nominal face need 1.125 blocks per square foot, or 112.5 per 100 square feet. This applies to 6, 8, 10 and 12 in wide blocks.
How many bricks are in a square metre?
About 60. A UK standard brick of 215 × 65 mm face with 10 mm joints works out at 59.3 per square metre of half-brick wall, and about 119 for a one-brick-thick wall.
How many blocks do I need for a 100 ft wall 4 ft high?
A 100 × 4 ft wall is 400 square feet, which needs 450 standard 8 × 8 × 16 blocks before waste, or 473 with a 5% allowance.
What size is a standard brick in the US?
The most common US brick is modular, with an actual size of 3-5/8 × 2-1/4 × 7-5/8 in and a nominal size of 4 × 2-2/3 × 8 in including the mortar joint.
What is the difference between nominal and actual size?
Actual size is the unit as manufactured. Nominal size adds one mortar joint, so an 8 × 8 × 16 block is actually 7-5/8 × 7-5/8 × 15-5/8 in and lays up on a 16 × 8 in module with 3/8 in joints.
How much waste should I allow for bricks and blocks?
Many estimators start at about 5% for plain walls and go higher for walls with many openings, corners, piers or cut units. Check the allowance against your own past jobs.
Does the calculator work out mortar?
Yes, approximately. It multiplies the mortar bed depth by the joint cross-section around each unit (full bed for solid units, two face shells for hollow block), adds your waste allowance and divides by the bag yield you enter. Grout fill, ties, reinforcement and structural design still need to be estimated separately.
Do I need an account to download the result?
No. All calculations, local file processing and exports on this page are free, without an account.
Where are my inputs stored?
The tool keeps inputs in this browser tab. It does not upload them or create a cloud copy. Save or download anything you want to keep before leaving the page. Standard site analytics may operate independently of the tool.
Can I work in metric instead of imperial?
Yes. Use the Imperial / Metric switch above the inputs. Imperial (feet, inches, pounds, gallons) is the default; switching converts every dimensional field and result, and your choice is remembered across the free tools in this browser.
Further reading
- 1970s brick veneer house template
- Typical exterior wall assemblies
- Wall build-ups template
- All materials & quantities tools
- All free architecture & construction tools
- Harth resource library
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