Brick Calculator
Bricks for a wall from its size, your brick and your joint, with doors and windows taken out, and mortar bags from a maker’s stated yield or your own figure.
The working
Gross area = Wall length × Wall height
= 20 ft × 8 ft
= 160 sq ft
Bricks = Net area × 144 ÷ Face area in sq in
Bricks laid
bricks
Waiting on you
Choose a brick size, or enter your own brick’s length and height from your supplier.
- Net wall area
- 160ft²
Enter the wall’s length and height, or its area, and any doors and windows. Enter your own brick’s length and height and the joint you will lay, or choose one of the Brick Industry Association’s sizes. The calculator counts bricks by area, rounds up once to whole bricks, checks the count course by course, and adds only the allowance you enter. Mortar bags come from the figure on your bag, or from a manufacturer’s published yield.
How this calculator works
Only your inputs and exact unit conversions. Where a figure comes from anywhere else, it is recorded below with its source.
- Formula version
- 1.0.0
- Last reviewed
- 2026-09-30
- External data
- 7 sources
- Category
- Materials
What this calculates
The number of bricks in a wall one brick thick (or as many layers as you enter). The count comes from the wall’s area and the area of one brick face with its joint. Doors and windows come out first, and the answer is rounded up once to whole bricks. Mortar bags follow from the brick count when there is a yield per bag to divide by.
The Brick Industry Association (BIA) calls this the wall-area method: "multiplying the net wall area (gross areas less areas of openings) by known quantities of material required per square foot" (Technical Note 10, February 2009). The count here does that with the quantity worked out from your own brick and joint.
Why about seven bricks per square foot
One brick with its joint covers a face of (length + joint) × (height + joint). A modular brick is specified at 7 5/8 × 2 1/4 in, and BIA’s Table 1 gives it a 3/8 in joint, so its face is (7.625 + 0.375) × (2.25 + 0.375) = 8 × 2.625 = 21 sq in. A square foot is 12 × 12 = 144 sq in, so a square foot of wall takes 144 ÷ 21 = 6.857143 bricks: that is the "about seven".
BIA’s Table 4 prints a different number for the same brick, 675 per 100 sq ft. It works from the nominal size, 4 × 2 2/3 × 8 in, which is the brick plus its intended joint and fits three courses to 8 in: the face is 8 × 2.666667 = 21.333333 sq in, and 144 ÷ 21.333333 = 6.75 per sq ft. Table 1’s third note says why the two can differ: "Actual bed joint thicknesses vary based on vertical coursing and actual brick height". A joint of exactly 3/8 in makes three courses 7 7/8 in, and the mason spreads the difference, about 0.42 in a bed joint instead of 0.375, to reach 8 in. The gap is 1.59% (6.8571 against 6.75), and both are on the page as choices.
Glen-Gery’s calculator page lists 6.86 pieces per sq ft for its modular size (2 1/4 × 7 5/8 in) and 6.55 for its standard (2 1/4 × 8 in). The arithmetic reproduces them with a 3/8 in joint: 144 ÷ 21 = 6.8571, and 144 ÷ ((8 + 0.375) × (2.25 + 0.375)) = 144 ÷ 21.984375 = 6.5501. BIA’s Table 4 prints 655 per 100 sq ft for its standard brick, the same. Queen, King and other sizes are sold in ranges, so no size of them is offered here: enter yours.
Bricks = Net area × 144 ÷ Face area in sq in × Layers. The count is printed exactly, then rounded up once, at the end. In metric the nominal modular face is 0.2032 m × 0.0677333 m, and 1 ÷ (0.2032 × 0.0677333) = 72.6564 bricks per m².
Nominal, specified and actual sizes: the joint is counted once
BIA’s Technical Note 10 defines three sets of dimensions. Nominal dimensions are the specified size "plus the intended thickness of its intended mortar joint". Specified dimensions are the size the brick is made to, "without consideration for mortar", and the ones used to order it. Actual dimensions are what the brick measures, "generally within a tolerance of the specified dimensions".
The joint belongs with a specified or measured size, never with a nominal one. Adding a 3/8 in joint to the nominal modular 8 × 2 2/3 in counts it twice: (8 + 0.375) × (2.666667 + 0.375) = 25.473958 sq in, which gives 5.6528 bricks per sq ft instead of 6.75, 16.25% short. Choose your own size and say which kind of size you have; the calculator adds your joint once to the length and once to the height of a specified size, and none to a nominal one.
Sizes vary by maker: BIA says "a brick name can vary from manufacturer to manufacturer" and recommends ordering by specified size, width first, then height, then length, and its Table 2 lists ranges for Queen, King and the closure and engineer standard sizes. BIA’s notes are written for fired clay brick and it does not advise using them for concrete or fly ash brick. ASTM C216, C62 and C652, which set the tolerances, are sold and were not read for this page.
Doors, windows and the course check
Each size of opening is count × width × height, and all of them come off the gross wall area before bricks are counted, as BIA’s wall-area method does.
With length and height, the calculator also counts course by course: courses = wall height ÷ face height and bricks per course = wall length ÷ face length, each rounded up, because a part course or a part brick still uses a unit cut on site. On a wall that fits the module the two methods agree. On a 25 × 7 ft wall of the modular 7 5/8 × 2 1/4 in brick with a 3/8 in joint they do not: 300 ÷ 8 = 37.5, so 38 per course, and 84 ÷ 2.625 = 32 courses, 1216 bricks, against 175 × 144 ÷ 21 = 1,200, or 1200, by area. Both numbers are shown.
The course check is on the gross wall, with no openings taken out, and it does not model running-bond half bricks, cut ends or a mason spreading the joints to fit a module.
- Courses of the 8 × 2.625 in module and of the 8 × 2 2/3 in nominal face, by wall height: 2 ft: 24 ÷ 2.625 = 9.1429, and 24 ÷ 2.666667 = 9; 3 ft: 36 ÷ 2.625 = 13.7143, and 36 ÷ 2.666667 = 13.5; 4 ft: 48 ÷ 2.625 = 18.2857, and 48 ÷ 2.666667 = 18; 6 ft: 72 ÷ 2.625 = 27.4286, and 72 ÷ 2.666667 = 27; 8 ft: 96 ÷ 2.625 = 36.5714, and 96 ÷ 2.666667 = 36; 10 ft: 120 ÷ 2.625 = 45.7143, and 120 ÷ 2.666667 = 45.
Layers through the wall
A wall two bricks thick, laid as two layers side by side, takes twice the bricks of one layer: the count is multiplied by the number of layers you enter, before rounding. Headers that tie layers together, and the collar joint between them, are not modelled. BIA’s Table 6 corrects the count for bonds that use headers: its own example, a standard brick in common bond with full headers every fifth course, is 655 + (1/5 × 655) = 786 per 100 sq ft. It is quoted, not applied.
Waste allowance and price
Both are yours, optional and blank. No allowance is assumed: breakage and cuts depend on the brick, the pattern and the crew. With an allowance, bricks to order = exact bricks × (1 + allowance ÷ 100), rounded up once. The allowance is never added to mortar. With a price per brick, the cost is the bricks to order, or the whole bricks laid if there is no allowance, times your price. A price quoted per thousand is divided by 1,000 first.
BIA’s Technical Note 10 says, "as a general rule, at least 5 percent is added to the net brick quantities delivered to the jobsite", that allowances "vary" and that job conditions or experience "may warrant using a higher percentage". It is quoted, not applied.
Mortar
Mortar bags = whole bricks ÷ bricks per bag, rounded up. The yield per bag is printed on the bag or in its data sheet. It changes with the product, the bag, the brick and how the mortar is laid, so the calculator uses your figure, or a manufacturer’s stated one that you choose.
QUIKRETE Mortar Mix No. 1102 (Type N) and Mason Mix No. 1136 (Type S): an 80 lb bag lays "up to" 37 "standard bricks" (data sheets revised November 2020). "Up to" is a maximum, so the result is the fewest bags, and the sheets do not say whether they allow for waste. Sakrete Mortar Mix Type S (Rev. 05/18): 18, 26 or 35 "standard bricks" per 40, 60 or 80 lb bag, approximate, and "the yield above does not allow for waste and spillage". SPEC MIX Mortar Cement & Sand: for an 80 lb bag, 39 to 41 Modular Brick, 33 to 35 Queen Sized, 26 to 28 King Sized and 23 to 25 Utility, "typical waste" included. A range is worked at both ends, never averaged.
None of the three sheets gives a brick’s dimensions: "standard brick", "Modular Brick" and the rest are names, not sizes. The figures are offered as the makers print them, and the working says so each time one is chosen. A QUIKRETE mortar yield for its 10, 40, 60 or 94 lb or its 25 or 30 kg bags was not found in the sources reviewed, and the 80 lb figure is not prorated to them.
No mortar type is recommended here. The QUIKRETE sheets refer to "Appendix XI of ASTM C270" for choosing one; that standard is sold and was not read.
What the sources say about mortar, waste and bond (quoted, not applied)
Each has a record below. None of these figures enters a result.
- BIA Technical Note 10, Table 4, mortar in the wall, theoretical and not including waste: modular brick 5.5 cu ft per 100 sq ft with a 3/8 in joint (6.9 with 1/2 in), or 8.1 cu ft per 1000 brick (10.3); standard brick 14.5 cu ft per 1000 brick (17.8). "The commonly used rule of thumb is appropriate: 1 cubic foot of loose, damp sand will yield about one cubic foot of mortar."
- BIA: "Masons frequently use a rule of thumb that eight bags of masonry cement will lay 1000 modular brick. This is a very rough estimate and includes an unspecified amount of waste." BIA adds "15 to 25 percent" to net mortar quantities as a general rule. The note gives volumes and bags of masonry cement, not the volume of a bag of the mixes above, and no bag volume was found on the sheets read.
- BIA Table 4 counts, per 100 sq ft with no waste: Modular 675, Engineer Modular 563, Closure Modular 450, Roman 600, Norman 450, Engineer Norman 375, Utility 300, Standard 655. They are the calculator’s own numbers for the sizes offered, and are shown beside them.
What it does not decide
No bond layout or cut list, no headers, no wall ties, no flashing, no footing, no lintels, no mortar type and no structural check. Those come from your plans, your building department and your engineer. Brick laid flat as paving and concrete blocks are not counted here.
A 30 × 8 ft wall with two 3 × 4 ft windows
The wall, the windows, the 5% allowance, the brick and the mortar product are example inputs, not recommendations. The brick is BIA’s modular size, specified 7 5/8 × 2 1/4 in, with the 3/8 in joint of its Table 1. The mortar is the Sakrete Mortar Mix Type S 80 lb option: approx. 35 "standard bricks" per bag, nothing allowed for waste.
- Wall
- 30 ft × 8 ft
- Windows
- 2 × 3 ft × 4 ft
- Brick
- Modular, specified 7 5/8 × 2 1/4 in + 3/8 in joint (face 8 × 2.625 in = 21 sq in)
- Layers
- 1
- Your allowance
- 5%
- Mortar
- Sakrete Mortar Mix Type S, 80 lb: approx. 35 "standard bricks" per bag
- 01Gross area= 30 × 8= 240 sq ft
- 02Windows= 2 × 3 × 4= 24 sq ft
- 03Net area= 240 − 24= 216 sq ft
- 04Bricks= 216 × 144 ÷ 21= 1,481.143
- 05Whole bricks= 1,481.143, rounded up= 1482 bricks
- 06Course check, gross wall= 96 ÷ 2.625 = 36.5714 courses, rounded up to 37; 360 ÷ 8 = 45; 37 × 45= 1665 bricks, windows not taken out
- 07To order with your 5%= 1,481.143 × 1.05 = 1,555.2, rounded up= 1556 bricks
- 08Mortar bags= 1482 ÷ 35 = 42.342857, rounded up= 43 bags
1482 laid, 1556 to order with your 5%; 43 bags of mortar
Bricks per area, by BIA brick size
Before any allowance and before doors and windows, one layer thick. Each per sq ft cell is 144 ÷ the face area in sq in; per 100 and per 1,000 sq ft multiply it; per m², 1 ÷ (face length in m × face height in m). The sizes and the last column are the Brick Industry Association’s (Technical Note 10, Tables 1, 2 and 4, recorded below). A nominal size already includes its joint; a specified size gets 3/8 in added once each way.
| Brick | Face module | Per sq ft | Per 100 sq ft | Per 1,000 sq ft | Per m² | Table 4, per 100 sq ft |
|---|---|---|---|---|---|---|
| Modular, 4 × 2 2/3 × 8 in nominal | 8 × 2.666667 in = 21.333333 sq in | 6.75 | 675 | 6,750 | 72.6564 | 675 |
| Engineer modular, 4 × 3 1/5 × 8 in nominal | 8 × 3.2 in = 25.6 sq in | 5.625 | 562.5 | 5,625 | 60.547 | 563 |
| Closure modular, 4 × 4 × 8 in nominal | 8 × 4 in = 32 sq in | 4.5 | 450 | 4,500 | 48.4376 | 450 |
| Roman, 4 × 2 × 12 in nominal | 12 × 2 in = 24 sq in | 6 | 600 | 6,000 | 64.5835 | 600 |
| Norman, 4 × 2 2/3 × 12 in nominal | 12 × 2.666667 in = 32 sq in | 4.5 | 450 | 4,500 | 48.4376 | 450 |
| Engineer Norman, 4 × 3 1/5 × 12 in nominal | 12 × 3.2 in = 38.4 sq in | 3.75 | 375 | 3,750 | 40.3647 | 375 |
| Utility, 4 × 4 × 12 in nominal | 12 × 4 in = 48 sq in | 3 | 300 | 3,000 | 32.2917 | 300 |
| Modular, 3 5/8 × 2 1/4 × 7 5/8 in specified | (7.625 + 0.375) × (2.25 + 0.375) = 21 sq in | 6.8571 | 685.71 | 6,857.1 | 73.8097 | 675 |
| Standard, 3 5/8 × 2 1/4 × 8 in specified | (8 + 0.375) × (2.25 + 0.375) = 21.984375 sq in | 6.5501 | 655.01 | 6,550.1 | 70.5048 | 655 |
Table 4 rounds to a whole brick (Engineer Modular is 562.5 here, 563 there). The two modular rows differ because a 3/8 in joint and a nominal 2 2/3 in course are different modules: 685.71 against 675, 1.59%. Adding a 3/8 in joint to the nominal 8 × 2 2/3 in counts it twice: 25.473958 sq in, 565.28 per 100 sq ft, 16.25% short.
What it assumes
- 01A wall of one layer of brick, unless you enter more layers.
- 02Every brick has the same face, laid as a stretcher in courses of that face’s height.
- 03Doors and windows are rectangles, taken out of the gross area.
- 04The count is by area and rounded up once; the course check uses the gross wall.
- 05Waste, prices, bricks per bag and the number of layers other than one apply only when you enter or choose them.
- 06Mortar uses the whole bricks laid, never your allowance.
What it does not do
- No bond layout or cut list: running-bond half bricks, cut ends and closures are not modelled.
- Headers, collar joints and bonds that use headers change the count (BIA Technical Note 10, Table 6); none is applied.
- Where two walls meet, measuring both to the outside corner counts the corner twice: wall thickness × height.
- A joint that differs from the coursing (three courses to 8 in) changes the count: choose your own brick and joint, or the nominal size, to match what will be laid.
- No wall ties, flashing, lintels, footing, reinforcement, mortar type or structural advice.
- Brick laid flat as paving and concrete blocks are not counted. BIA writes its notes for fired clay brick.
- The makers’ mortar yields are for "standard bricks" or named types whose sizes their sheets do not give. For any other brick, use the figure on your bag.
Common questions.
- How do I calculate how many bricks I need?
- Work out the wall’s area in square feet and take out the doors and windows. Multiply by 144 and divide by the area of one brick face in square inches, joint included. For the modular brick with a 3/8 in joint that is 144 ÷ 21 = 6.8571 bricks per square foot. Round up once, at the end, and add any allowance you choose on top.
- How many bricks per square foot?
- It depends on the brick and the joint, so the answer is 144 ÷ the face area. Modular brick, specified 7 5/8 × 2 1/4 in with a 3/8 in joint: 144 ÷ 21 = 6.8571. The same brick at BIA’s nominal size, 8 × 2 2/3 in: 144 ÷ 21.333333 = 6.75. BIA’s standard brick, 8 × 2 1/4 in with a 3/8 in joint: 144 ÷ 21.984375 = 6.5501. A Utility brick, 12 × 4 in nominal: 144 ÷ 48 = 3.
- How many bricks per 100 square feet?
- 100 × 144 ÷ the face area. Modular brick with a 3/8 in joint: 100 × 144 ÷ 21 = 685.71, so 686 whole bricks. At BIA’s nominal size: 100 × 144 ÷ 21.333333 = 675, and BIA’s Table 4 prints 675. For 1,000 sq ft the same figures are 6,857.14 and 6,750. All before any allowance and before doors and windows come out.
- How many bricks do I need for a 10 × 10 ft wall?
- A 10 × 10 ft wall is 100 sq ft before doors and windows: 685.71, so 686 whole bricks, for the modular brick with a 3/8 in joint, or 675, so 675, at BIA’s nominal size. A 20 × 8 ft wall is 160 sq ft: 160 × 144 ÷ 21 = 1,097.143, so 1098; take out a 3 × 7 ft door and it is 139 sq ft: 139 × 144 ÷ 21 = 953.143, so 954.
- How much area will 1,000 bricks cover?
- 1,000 ÷ bricks per square foot. Modular brick with a 3/8 in joint is 144 ÷ 21 = 6.857143 per sq ft, so 1,000 ÷ 6.857143 = 145.83 sq ft. At BIA’s nominal size it is 144 ÷ 21.333333 = 6.75, so 1,000 ÷ 6.75 = 148.15 sq ft. One layer thick, with no waste; the result panel gives the figure for your own brick.
- How many bags of mortar do I need for 100 or 1,000 bricks?
- It depends on the mortar, the bag and the brick, so the answer is the bag’s own figure. QUIKRETE Mortar Mix No. 1102 and Mason Mix No. 1136 lay up to 37 "standard bricks" per 80 lb bag, so 100 ÷ 37 = 2.7, at least 3 bags, and 1,000 ÷ 37 = 27.03, at least 28. Sakrete Mortar Mix Type S lays approximately 35 "standard bricks" per 80 lb bag, with nothing allowed for waste: 100 ÷ 35 = 2.86, so 3 bags, and 1,000 ÷ 35 = 28.57, so 29. SPEC MIX Mortar Cement & Sand lays 39 to 41 Modular Brick per 80 lb bag with typical waste included: 1,000 ÷ 41 = 24.39 and 1,000 ÷ 39 = 25.64, so 25 to 26 bags. None of the sheets gives the brick’s size. For mortar mixed on site, BIA quotes a mason’s rule of thumb of eight bags of masonry cement per 1000 modular brick, "very rough" and with an unspecified waste included; it is quoted, not applied.
- What is the difference between nominal, specified and actual brick size?
- BIA’s Technical Note 10 defines them. Nominal is the specified size plus the intended joint, a round number that gives a module (a modular brick is 4 × 2 2/3 × 8 in). Specified is the size the brick is made to, without mortar, and the one to order by (3 5/8 × 2 1/4 × 7 5/8 in). Actual is what a brick measures, generally within a tolerance of the specified size that the ASTM standards set; those standards are sold and were not read for this page.
- Do I add the mortar joint to the brick size?
- Only to a specified or measured size. A nominal size already includes one joint, and adding it again counts it twice: (8 + 0.375) × (2.666667 + 0.375) = 25.473958 sq in instead of 21.333333, which gives 5.6528 bricks per sq ft instead of 6.75, 16.25% short. Choose your own size and say which kind of size you have; the calculator adds your joint once to the length and once to the height of a specified size.
- Why do two brick calculators give different counts for the same brick?
- They use different modules. Modular brick with a 3/8 in joint is 144 ÷ 21 = 6.8571 per sq ft (Glen-Gery’s list prints 6.86); BIA’s Table 4 prints 675 per 100 sq ft, 6.75, from the nominal 8 × 2 2/3 in face. The 3/8 in joint makes three courses 7 7/8 in; the nominal size fits them to 8 in. The gap is 1.59%. A different joint, a size that is not modular or a calculator that adds the joint to a nominal size moves the count more.
- How much waste should I add?
- No allowance is assumed here: it depends on the brick, the pattern and the crew, so it is yours to enter. BIA’s Technical Note 10 says as a general rule at least 5 percent is added to the net brick quantities delivered to the jobsite, and that job conditions or experience may warrant more. That is quoted, not applied. The allowance is worked on the exact count and rounded up once.
- How many bricks in a square metre?
- 1 ÷ (face length in m × face height in m). BIA’s nominal modular face is 0.2032 m × 0.0677333 m: 72.6564 per m² (BIA’s Table 4 prints 727 per 10 m²). Modular brick with a 3/8 in joint is 1 ÷ (0.2032 × 0.066675) = 73.8097 per m². Enter metric sizes and the calculator does the conversion: 1 in = 25.4 mm exactly.
- Does a wall two bricks thick need double the bricks?
- Two layers side by side take twice the bricks, so enter 2 under Layers through the wall and the count is multiplied before rounding. Headers, which tie layers together, take more, and BIA’s Table 6 corrects for them: a standard brick in common bond with full headers every fifth course is 655 + (1/5 × 655) = 786 per 100 sq ft. That correction is quoted, not applied.
- How much do 1,000 bricks cost?
- Enter your supplier’s price per brick under Layers, waste and price and the calculator multiplies it out; no price is assumed. 1,000 bricks at your price is 1,000 × that price. A price quoted per thousand divided by 1,000 is the price per brick. Mortar at your price per bag is separate.
- What about concrete blocks?
- They are a different product with their own face sizes and yields: see the concrete block calculator, which counts blocks by the same wall-area method. Brick laid flat as paving is not counted here either.
Where people go next
Ordered by what usually comes next in the same job, not by keyword.