Brick Calculator
The module is the brick length plus the joint, times the brick height plus the joint. Bricks per square foot are 1 divided by that module, converted from the per-m² count. The metric toggle keeps the per-m² rate. The count is the wall area times that rate, times waste, rounded up. Mortar bags divide that count by 37, the “up to 37 standard bricks” line on the QUIKRETE 80 lb Mortar Mix sheet. The starting brick is the size on the form, a common modular size to edit, not a rule.
Last reviewed: 2026-10-28 · How we calculate
How we calculate
Module length = (brick length + joint) ÷ 1,000. Module height = (brick height + joint) ÷ 1,000. Bricks per m² = 1 ÷ (module length × module height). Bricks = ceil(wall area × bricks per m² × (1 + waste %)). Mortar bags = ceil(bricks ÷ bricks per bag), only when bricks per bag is greater than zero.
Worked example
A 100 sq ft wall of 8 in by 2.5 in bricks with a 0.5 in joint is 593 bricks, about 5.65 per sq ft.
Bricks first, then the mortar bags
A brick wall is a brick count and a mortar count, and they come from different places. The bricks come from the face size plus the joint. The mortar bags come from how many bricks one bag lays. QUIKRETE Mortar Mix says an 80 lb bag lays up to 37 standard bricks, and that 37 is the starting yield. A larger brick or a fatter joint uses more mortar, so edit 37 when the bag says something else.
Measuring a brick wall
Brick counts are a module, not a picture of the bond. The face of a 215 mm brick plus a 10 mm joint is 225 mm. The height plus the joint is 75 mm. The face module is 0.225 times 0.075, which is 0.016875 square metres. One divided by that is 59.259 bricks per m². Ten square metres is 592.59, which rounds up to 593. Five percent waste multiplies before the rounding. A queen closer, a header course, or a basketweave changes the module. If the bond is not a simple stretcher face, this count is only a start and you should add waste you can explain or measure a sample bay.
How the wall becomes bricks and mortar
The 215 by 65 by 10 starting point is labelled as a common modular size. A 190 mm brick, a 50 mm slip, or a 73 mm height will not land on 593. Change the fields before you order. Openings should already be out of the wall area. A door of about 2 square metres left in a 10 square metre wall is two square metres of brick you do not need. The render page subtracts 1.9 and 1.2 for a door and a window if you want those allowances as a cross-check. Corners share a brick between two faces. If you add two elevations, the corner brick is counted twice. Subtract the shared perpends or accept a little extra.
Ordering mortar from bricks per bag
Mortar starts from the cited 37 bricks per 80 lb bag. The mortar calculator on this site divides an area by a coverage in square feet per bag (square feet per bag on the metric toggle), which is a different way to say the same thing, and that coverage is also something you type. If the bag says it lays 30 bricks, type 30 and 593 bricks become 20 bags. If the bag talks in m², use the mortar page instead and do not also add this bag line. Do not use both as if they were extra to each other.
Checking a brick order
A footing under the wall is the footing calculator. Cinder block is a larger module on its own page. There is no price per thousand. Brick suppliers often sell by the thousand. Divide the brick count by 1,000 if that is how they quote, and keep the remainder. Waste is already in the count if you set it.
Brick fields and starting values
Wall area starts at 100 sq ft. Wall area in square feet. Brick length starts at 8 in. Brick length in inches, or millimetres on the metric toggle. Brick height starts at 2.5 in. Brick height in inches, or millimetres on the metric toggle. Mortar joint starts at 0.5 in. Mortar joint. A 3/8 in joint is 0.375 in inches, or millimetres on the metric toggle. Waste allowance starts at 5 %. Cuts and breakage. Five percent is only the number in the field. Bricks per mortar bag starts at 37. 37 is the “up to 37 standard bricks” line on the QUIKRETE 80 lb Mortar Mix data sheet, checked 27 October 2026. The same sheet says up to 13 standard blocks, which is a different wall.
Mortar bags for a modular brick wall
Bricks per bag is 37, the “up to 37 standard bricks” line on the QUIKRETE Mortar Mix data sheet for an 80 lb bag. The brick face here is 215 × 65 mm with a 10 mm joint and 5% waste.
| Wall | Bricks | 80 lb mortar bags |
|---|---|---|
| 10 m² | 623 | 17 |
| 20 m² | 1245 | 34 |
| 40 m² | 2489 | 68 |
QUIKRETE’s “standard brick” is 8 × 2 × 4 in. A different brick or a thicker joint changes both columns. The sheet also says one 80 lb bag lays up to 13 standard blocks, which is a different wall.
Common mistakes
- Leaving 215 by 65 in place when you are buying a different brick.
- Expecting mortar bags while the yield is 0.
- Using the cinder-block module for clay brick.
- Forgetting openings in the wall area.
- Treating bricks per bag from a different mortar as if it were yours.
- Adding a price.
Frequently asked questions
How many bricks are in a square metre?
For a 215 by 65 mm brick and a 10 mm joint, about 59.26, and a 10 m² wall rounds up to 593 bricks before waste.
How much mortar do I need?
Only after you type how many bricks one bag lays. Otherwise the bag line is 0. The mortar calculator can also take a square-metre coverage.
Is 215 by 65 required?
No. It is a common size sitting in the fields so you can see a count. Measure your brick.
Does the joint size matter?
Yes. It is part of the module in both directions.
What about half bricks and corners?
They are inside the waste percentage and the cuts. The formula is a stretcher face module.
Is there a price?
No.