Brick Calculator
Enter the wall's length and height, say whether it is one brick or half a brick thick, and give the size of your brick and the mortar joint. You get the brick count, wall volume and mortar estimate.
Created by the Reeliy Editorial Team. Last updated: Oct 19, 2026
Calculating how many bricks you need
A wall is a flat pattern of bricks separated by mortar. Divide the area of the wall by the area one brick takes up on the face, joint included, and you have the number of bricks. The calculator rounds the answer up to a whole brick.
The basic formula
bricks = (wall length × wall height) ÷ [(face width + joint) × (face height + joint)]The face is the side of the brick you see in the finished wall.
What counts as the face depends on how thick the wall is. In a single brick wall the brick's length runs through the wall, so the face you see is the brick's width by its height. In a half brick wall the brick lies along the wall, so the face is its length by its height, and the wall is as thick as the brick is wide. Pick the option that matches your wall, as it changes both the count and the volume.
Including the mortar joint
Each brick sits in a bed of mortar below it and beside it, so it effectively occupies a slightly larger rectangle than its own face. The calculator adds the joint thickness to both face dimensions before dividing, using one joint value for the horizontal bed joints and the vertical head joints.
The mortar needed is estimated from one bed joint and one head joint per brick. In symbols, each brick uses roughly joint × wall thickness × (face width + face height) of mortar. The figure is for the joints themselves, so it does not allow for mortar lost in mixing or dropped on the ground. Plan to mix more than the number shown.
Accounting for waste
Some bricks arrive chipped, some are cut to fit at corners and openings, and some break on site. The waste percentage multiplies the count before it is rounded up.
bricks to buy = ⌈ bricks × (1 + waste ÷ 100) ⌉5% is the default. Intricate patterns, many openings or soft bricks justify more.
Brick calculation examples
US example. A garden wall is 12 ft long and 6 ft high, built one half brick thick from modular bricks that measure 3⅝ in wide, 2¼ in high and 7⅝ in long, with a ⅜ in joint (0.375 in). The face is the length by the height: (7.625 + 0.375) × (2.25 + 0.375) = 8 × 2.625 = 21 in². The wall is 12 × 6 = 72 ft², which is 10,368 in², so 10,368 ÷ 21 = 493.7 bricks. With 5% waste that is 518.4, rounded up to 519 bricks. The wall is 3.625 in thick, so its volume is 72 × 3.625 ÷ 12 = 21.75 ft³, and the mortar comes to about 3.84 ft³.
Metric example. A wall 5 m long and 2.4 m high is built half a brick thick from 215 × 102.5 × 65 mm bricks with a 10 mm joint. The face is (215 + 10) × (65 + 10) = 225 × 75 = 16,875 mm². The wall is 12 m², or 12,000,000 mm², so 12,000,000 ÷ 16,875 = 711.1 bricks. With 5% waste that is 746.7, so order 747 bricks. At 0.55 per brick, that is 747 × 0.55 = 410.85.
| Brick (width × height × length) | Joint | Wall type | Bricks per area, no waste |
|---|---|---|---|
| 3⅝ × 2¼ × 7⅝ in | ⅜ in | Half brick | 6.86 per ft² (685.7 per 100 ft²) |
| 102.5 × 65 × 215 mm | 10 mm | Half brick | 59.3 per m² |
Does the bond matter?
The calculator does not ask for a bond. Running (stretcher) bond, stack bond and most other patterns put the same number of bricks in the same area of wall, because each brick still occupies one face and one joint. The pattern changes how many bricks you cut, which is why complicated bonds, curves and many corners deserve a higher waste figure.
Bond does matter for thicker walls. Where courses of headers (bricks turned end-on) are built into the wall, as in English or Flemish bond, the wall is a full brick thick. Choose single brick thickness for those.
Common mistakes
- Using nominal sizes and a joint. Some brick sizes quoted in catalogs already include the joint. Enter the actual brick size with the joint separately, or enter the nominal size and set the joint to 0.
- Forgetting openings. The wall is treated as a solid rectangle. To allow for a window or door, calculate the bricks for that opening with the same tool and subtract the count.
- Mixing units. Each field has its own unit menu, so a wall in feet and a brick in millimetres works, but check that every menu says what you think it says.
- Skipping the waste. Rounding up the exact figure is not enough on its own. Keep a few percent of margin.
Brick walls often come with other jobs. Use the paint calculator for finishing nearby surfaces, the tile calculator for floors and splashbacks, the concrete calculator for the footing, and the square footage calculator for the wall area.
These are planning estimates. Brick sizes, joints and site conditions vary, so confirm quantities with your supplier or mason. See our disclaimer.
Frequently asked questions
How many bricks are in a square foot of wall?
With a modular brick (3⅝ × 2¼ × 7⅝ in) and a ⅜ in joint, a half-brick wall takes about 6.86 bricks per square foot, before waste.
How many bricks are in a square metre of wall?
A standard 215 × 102.5 × 65 mm brick with a 10 mm joint in a half-brick wall takes about 59 bricks per square metre, before waste.
What is the difference between a half brick and a single brick wall?
A half brick wall is as thick as the brick is wide, with the bricks laid along the wall. A single brick wall is as thick as the brick is long, with the bricks laid across the wall.
How much waste should I allow?
The calculator starts at 5%. Increase it for complex bonds, many cuts or fragile bricks. A larger allowance costs little compared with a short delivery.
Does the mortar estimate include waste?
No. It covers the joints between bricks only. Mortar is also lost in mixing and handling, so mix more than the figure shown.
Cite this calculator and page
If you use this page in your work, you can cite it as:
Reeliy Editorial Team. (2026). Brick Calculator. Reeliy. https://reeliy.com/calculators/brick-calculator“Brick Calculator.” Reeliy, 2026, https://reeliy.com/calculators/brick-calculator.