A brick calculator works out how many bricks or concrete blocks a wall needs from its length, height and openings, and how many bags of mortar go with them. Contruva’s free brick calculator handles several walls at once, subtracts doors and windows, and covers modular, queen and king brick, Canadian metric modular brick, 8 inch concrete block, or any custom size, with waste and mortar bags built in.
Open the free brick calculator in your browser. No login, no email, nothing to pay.
Open the free toolThe core formula is short: net wall area × units per square foot × wythes, plus waste. The number that trips people up is units per square foot, because it depends on the brick’s face size and the mortar joint, not the size printed on the pallet. Below is how the calculator gets it, worked examples you can check by hand, and how to estimate mortar without guessing.
How to use the brick calculator
Feet and inches or metres and millimetres. Single wythe for a veneer, double for a two-brick-thick wall.
Length and height of each wall. Add as many as you need; the calculator totals the area.
Number of doors and windows (counted at 21 and 15 sq ft, or 1.95 and 1.4 m²), plus any other openings by area, such as a garage door.
Modular, queen, king, metric modular, 8 inch block or a custom size. The joint defaults to 3/8 inch or 10 mm.
Waste starts at 5%. Mortar bags use the units-per-bag figure for that product, which you can change to match the bag you buy.
How many bricks per square foot?
Units per square foot is 144 divided by the face area of one unit plus one joint in each direction. In metric, it’s 1,000,000 divided by the face in millimetres plus the joint. The calculator works from the actual face size, so the result changes if you change the joint.
| Unit | Face size (L × H) | Per sq ft at 3/8 in joint | BIA table (per sq ft) |
|---|---|---|---|
| Modular brick | 7⅝ × 2¼ in | 6.86 | 6.75 |
| Queen brick | 7⅝ × 2¾ in | 5.76 | 5.50 |
| King brick | 9⅝ × 2⅝ in | 4.80 | 4.55 |
| 8 × 16 concrete block | 15⅝ × 7⅝ in | 1.125 | n/a |
| Metric modular brick | 190 × 57 mm | 74.63 per m² at 10 mm | n/a |
| Metric block | 390 × 190 mm | 12.5 per m² at 10 mm | n/a |
The Brick Industry Association’s Technical Note 10 lists 675 modular brick per 100 sq ft, which is where the familiar 6.75 per square foot comes from. That figure uses the nominal 2⅔ inch course (three courses to 8 inches), while 2¼ inch brick with an exact 3/8 inch joint works out to 6.86. The BIA’s queen and king figures cover a range of specified sizes and joint widths, so they run a little lower than the single size in the calculator. The difference is about 2% on modular; your waste allowance covers it, but it’s worth knowing why two calculators can disagree.
For block, the 8 × 16 rule of thumb is 1.125 per square foot, and Canada Brick’s rule-of-thumb sheet says the same (checked November 2026). Canadian metric modular brick is listed by manufacturers such as Canada Brick at 190 × 57 × 90 mm. CSA A82 covers brick grades and size tolerances rather than fixing one size, so check the spec sheet for the brick you’re buying and use a custom size if it differs.
How to calculate bricks for a wall
| Step | Formula |
|---|---|
| Wall area | Length × height, for each wall, added up |
| Openings | Doors × 21 sq ft + windows × 15 sq ft + other openings |
| Net area | Wall area − openings |
| Units | Net area × units per sq ft × number of wythes |
| To order | Units × (1 + waste %), rounded up |
| Mortar bags | Units to order ÷ units per bag, rounded up |
If you know the real size of a door or window, put it in “other openings” instead of using the counted size. Big openings like garage doors and picture windows should always go in by area.
Worked examples
A modular brick wall with a door and two windows
One wall, 30 ft long and 8 ft high, with one door and two windows, modular brick at a 3/8 inch joint, single wythe, 5% waste, and a mortar bag that lays 37 brick.
30 × 8 = 240.
1 door × 21 + 2 windows × 15 = 51.
240 − 51 = 189.
144 ÷ (8 × 2.625) = 6.857 per sq ft. 189 × 6.857 = 1,296.
1,296 × 1.05 = 1,360.8, so 1,361.
1,361 ÷ 37 = 36.8, so 37 bags.
Two block walls
A 24 ft and a 16 ft wall, both 4 ft high, in 8 inch block with no openings, 5% waste, and 13 block per bag of mortar.
Area 96 + 64 = 160 sq ft · × 1.125 = 180 block · × 1.05 = 189 block · ÷ 13 = 14.5, so 15 bags of mortar.
Metric modular brick
A 10 m wall, 2.4 m high, no openings, 190 × 57 mm brick with 10 mm joints, 5% waste, 37 brick per bag.
Area 24 m² · 1,000,000 ÷ (200 × 67) = 74.63 per m² · 24 × 74.63 = 1,791 brick · × 1.05 = 1,881 · ÷ 37 = 50.8, so 51 bags.
Single vs double wythe
A wythe is one vertical layer of masonry, one unit thick. Most brick on new houses is a single-wythe veneer tied back to the framing or block behind it. Older solid masonry walls and some garden and retaining walls are two wythes, bonded with header courses or ties, with a collar joint between them.
| Wall type | Wythes | What it does to the count |
|---|---|---|
| Brick veneer on a framed or block wall | 1 | Net area × units per sq ft |
| Solid double brick wall | 2 | Double the brick; add mortar for the collar joint if it’s filled |
| Freestanding garden wall | Often 2 | Double, plus coping or cap units on top |
The double wythe setting in the calculator doubles the unit count. It doesn’t add mortar for a filled collar joint; BIA Technical Note 10 gives 3.13 cu ft of mortar per 100 sq ft of wall for a 3/8 inch collar joint if you need to add it. Header courses in bonds like common or Flemish bond also change the count; TN 10 has correction factors for those.
How much mortar do I need?
Mortar depends on the product, so the calculator asks how many units one bag lays and divides. Two very different products are sold as “mortar”, and the yields aren’t comparable:
- Pre-blended mason mix (cement, lime and sand in the bag, add water). Quikrete’s data sheet says one 80 lb (36 kg) bag of Type S Mason Mix lays up to 37 standard brick or 13 standard 8 × 8 × 16 block (checked November 2026). Those are the calculator’s defaults for brick and block.
- Masonry cement or Type N/S cement you mix with sand on site. A bag goes much further because you add the sand. Canada Brick’s rule of thumb is about 7 bags per 1,000 modular brick and 3 bags per 100 block, mixed at 1 part mortar to 2 to 3 parts sand, and about 1 cubic yard of sand per 1,000 brick. BIA notes the old “8 bags per 1,000 brick” rule is a very rough estimate.
For queen and king brick, the calculator scales the 37-brick yield by the mortar each size uses in BIA’s Table 4 at a 3/8 inch joint (8.1 cu ft per 1,000 modular brick, 12.2 for queen, 14.2 for king), which gives about 25 queen or 21 king per bag. They’re estimates; if your supplier has a better number, type it in.
Canada Brick’s rule-of-thumb sheet lists Type N for veneer walls and Type S for foundations below grade. Follow the drawings and your local building code for the job in front of you.
Waste, cuts and ordering
The calculator starts at 5% waste for breakage and cuts. Push it up for walls with lots of corners, openings, soldier courses or a pattern that needs half bricks, and for chipped or seconds stock. Round up to full cubes or pallets when you order, and buy the whole job from one production run so the colour matches.
- Measure each wall separately. Gables, bump-outs and returns are easy to miss on a single overall number.
- Use real opening sizes for big openings. A double garage door is far bigger than the 21 sq ft counted for a door.
- Don’t forget the extras. Sills, caps, lintels, ties, flashing and weep vents aren’t in the brick count.
Pricing the labour and the quote
Materials are the easy half of a masonry quote. The labour is what decides whether the job makes money: setup and scaffolding, the units your crew actually lays in a day on this kind of wall, cutting, cleanup and travel. Price it from your own crew’s production on past jobs, at a rate that covers wages, burden and overhead. The contractor hourly rate calculator works out that rate, and the markup calculator turns total cost into a price. For paver and stone work around the house, the paver calculator and gravel calculator cover the rest.
If you run a masonry crew, Contruva keeps your brick, block, mortar and labour rates in one price catalog, so a quote takes minutes and the customer can approve it and pay the deposit online. Crew hours and receipts roll into job costing, so you can see whether the wall you priced at 1,361 brick and three days took 1,500 and four. It’s one plan, Contruva Pro, at $249.99 CAD a month. Try it free for 7 days, no credit card needed.