Brick Calculator
How many bricks you need for a wall
A 20 by 8 ft wall takes 1,134 modular bricks including 5% waste, or 1,101 standard bricks, at 6.75 modular bricks per square foot. Enter your own wall length and height for the count in five common sizes, or your own brick and joint under More options, plus the mortar and sand to go with them.
How many bricks per square foot
The count comes from the brick's nominal face, which is the actual brick plus one mortar joint. A modular brick measures 7⅝ by 2¼ inches, and with a standard ⅜ inch joint it occupies 8 by 2⅔ inches of wall. That is 21.33 in², or 0.1481 ft², so a modular brick wall needs 6.75 bricks per square foot.
You will see "7 bricks per square foot" quoted almost everywhere, and it is a fine rule of thumb — it is 6.75 rounded up, which quietly builds in about 4% waste. This calculator uses the exact 6.75 instead, because waste is a separate field here and rounding it in twice would have you ordering bricks you do not need.
Brick size and coverage chart
Nominal face area includes the ⅜ inch mortar joint on the length and the bed. Counts are bare, before any waste.
| Brick type | Actual size (in) | Nominal face | Bricks per ft² | Per 100 ft² |
|---|---|---|---|---|
| Modular | 3⅝ × 2¼ × 7⅝ | 0.148 ft² | 6.75 | 675 |
| Standard | 3⅝ × 2¼ × 8 | 0.153 ft² | 6.55 | 656 |
| Engineer modular | 3⅝ × 2¾ × 7⅝ | 0.178 ft² | 5.63 | 563 |
| Queen | 3⅛ × 2¾ × 9⅝ | 0.217 ft² | 4.61 | 461 |
| Utility | 3⅝ × 3⅝ × 11⅝ | 0.333 ft² | 3.00 | 300 |
Modular and standard look almost identical on a pallet and differ by less than half an inch, but that half inch is a 3% difference in the count — about 34 bricks on a 1,100-brick wall. Check which one your supplier is quoting before you order. Queen and utility sizes cover far more wall per brick, which is exactly why they are popular on large veneer jobs: fewer units, fewer joints, less labour.
Worked example: a 20 × 8 ft garden wall
A wall 20 ft long and 8 ft high is 160 ft² of face. With 5% waste for cuts at the ends, that is 168 ft² to buy for. These are the figures this brick estimator returns:
| Brick type | Working | Bricks needed |
|---|---|---|
| Modular | 168 ÷ 0.148 | 1,134 |
| Standard | 168 ÷ 0.153 | 1,101 |
| Engineer modular | 168 ÷ 0.178 | 945 |
| Queen | 168 ÷ 0.217 | 775 |
| Utility | 168 ÷ 0.333 | 504 |
| If double wythe (modular) | 1,134 × 2 | 2,268 |
| Mortar for 1,134 modular | ~8 bags cement, or ~30 bags premixed | plus ~1 ton sand |
Deduct openings before you run it. A single 3 × 4 ft window is 12 ft², which is 81 modular bricks — enough to matter, though many bricklayers leave the deduction out on purpose so the offcuts around the opening are covered.
Single wythe, double wythe and cavity walls
This brick wall calculator counts the face of the wall, so it assumes one brick thickness. What you are building decides the multiplier:
- Brick veneer is a single wythe tied to a framed wall behind it. Face count, no multiplier. This is most modern house brickwork.
- Single-wythe garden wall, one brick thick and usually under 3 ft. Face count.
- Double wythe (solid) is two leaves bonded together. Double the count.
- Cavity wall is two wythes with a gap between them. Also double the count, plus wall ties.
A free-standing wall over about 3 ft usually wants to be double wythe or piered for stability, and anything load-bearing or over 4 ft is a job to check against local code. The count is the easy part; the footing under it is not.
Mortar and sand quantities
Mortar is the quantity people forget until the pallet arrives. For modular bricks with ⅜ inch joints:
| Approach | Per 1,000 bricks | Notes |
|---|---|---|
| Pre-mixed mortar, 80 lb bags | 25 to 30 bags | Roughly one bag per 30 to 40 bricks |
| Masonry cement + sand | ~8 bags masonry cement + ~1 ton sand | Cheaper in volume, needs mixing |
| Type N mortar | — | General above-grade use, most walls |
| Type S mortar | — | Below grade, retaining, high wind |
Buy more than you think. Running out mid-course means a batch made an hour later, and mortar colour shifts noticeably between batches once it dries. Mix only what you can lay in about 90 minutes, and never re-temper mortar that has begun to set by adding water.
Laying bricks flat for a patio
Used as a brick patio calculator, the numbers change, because a brick laid flat presents its bed face rather than its side. A modular brick lying down covers roughly 8 by 3⅝ inches, so you need about 4.5 to 5 bricks per square foot instead of 6.75 — meaningfully fewer than the same brick in a wall.
Paving brick is also a different product from wall brick. Look for brick rated SX (severe weathering) for anything exposed to freeze-thaw, and note that clay pavers are usually thinner and denser than facing brick. The base matters more than the brick: run the excavation and stone through the paver calculator, which covers base depth, bedding sand and edge restraint.
Waste, breakage and colour batches
- 5% for a plain rectangular wall with square ends.
- 10% for walls with openings, returns, or a soldier course.
- 15% for arches, curves, herringbone panels or heavy cutting.
Order the whole lot at once. Clay brick colour comes from the clay body and the kiln, and it varies visibly between production runs — a repair three years later with a fresh pallet will show. Keep 20 or 30 spares on site from the original batch and store them dry.
Bricklaying mistakes worth avoiding
- Counting the bare brick instead of the nominal face. Ignoring the joint over-orders by around 20%.
- Using the 7-per-ft² rule and then adding waste. That is waste counted twice.
- Wetting bricks like an old-school bricklayer. Modern extruded brick generally should not be soaked; follow the manufacturer.
- No weep holes or flashing in a veneer. The cavity must be able to drain, or water sits against the sheathing.
- Skipping wall ties or spacing them too far apart on veneer and cavity work.
- Laying in freezing weather. Mortar that freezes before it cures never reaches strength.
- Tooling joints too late. Strike them when the mortar is thumbprint-hard, not after it has set.
What the brick count assumes
Brick counts are wall area × (1 + waste) ÷ nominal face area, rounded up. Nominal face is the brick plus one ⅜ inch mortar joint on the length and the bed, which is how brick is specified and sold.
- Modular: 8 × 2⅔ in nominal = 21.33 in² = 0.14815 ft² = 6.75 per ft². Standard: 8⅝ × 2⅝ = 21.98 in² = 6.55 per ft². Engineer modular 5.63, queen 4.61, utility 3.00.
- Coverage constants are stored as exact fractions, not rounded decimals. Truncating modular coverage to 0.148148 instead of 8 × 8/3 ÷ 144 shifts the example wall from 1,134 bricks to 1,135 through rounding alone.
- Counts are single wythe. Double the result for a solid or cavity wall.
- Mortar quantities (25 to 30 pre-mixed bags, or 8 bags masonry cement plus a ton of sand, per 1,000 bricks) are planning figures. Actual use varies with joint thickness, brick absorption and how much you drop.
- Joint size is assumed to be ⅜ in throughout. A ½ in joint reduces the count by roughly 5%.
Reviewed September 2026.
Both unit systems. Metric mode measures in metres and m², and switches to the sizes metric suppliers sell: UK bricks (215 × 65 mm), Australian bricks (230 × 76 mm), Metric modular (200 × 75 mm). Any coverage you enter yourself is read as m².
Sources, checked
- Technical Note 10: Dimensioning and Estimating Brick Masonry, Brick Industry Association. 675 modular bricks per 100 ft² at a 3/8 in joint, and eight bags of masonry cement per 1,000.
Figures reviewed . Every worked example on this page is checked against the calculator above.
Brick Calculator: frequently asked questions
How many bricks are in a square foot?
6.75 modular bricks per square foot of wall face, including the ⅜ inch mortar joint. The widely quoted figure of 7 is that number rounded up, which builds in about 4% waste. Standard bricks work out at 6.55 per ft² and queen size at 4.61.
How many bricks in a wall 20 feet long and 8 feet high?
About 1,134 modular bricks for a single-wythe wall, which is 160 ft² plus 5% waste divided by 0.148 ft² per brick. A double-wythe version of the same wall needs 2,268.
Should I order extra bricks?
Yes. Add 5% for a plain rectangular wall, 10% if it has openings or returns, and 15% for arches, curves or heavy cutting. Order it all at once, because clay brick colour varies visibly between production batches.
How much mortar do I need for bricks?
Roughly one 80 lb bag of pre-mixed mortar per 30 to 40 bricks, so 25 to 30 bags per 1,000. Mixing your own takes about 8 bags of masonry cement per 1,000 bricks, the Brick Industry Association’s rule of thumb, plus roughly a ton of sand.
What is the difference between modular and standard brick?
Modular is 7⅝ inches long and standard is 8 inches, both 2¼ high. That small difference changes coverage from 6.75 to 6.55 bricks per square foot, about 3% on the total count. Check which your supplier quotes.
How many bricks do I need for a patio?
About 4.5 to 5 per square foot, because a brick laid flat presents its wider bed face rather than its side. That is noticeably fewer than the 6.75 per ft² a wall needs. Use brick rated SX for freeze-thaw exposure.
What is a wythe in bricklaying?
One continuous vertical thickness of brick. A veneer or garden wall is single wythe and uses the face count; a solid or cavity wall is two wythes and needs twice as many bricks, plus ties.
Do I subtract windows and doors from the brick count?
You can, and the calculator lets you by reducing the area you enter. A 3 × 4 ft window is 12 ft², or 81 modular bricks. Many bricklayers deliberately leave openings in the count so the extra covers cutting around them.