Brick Calculator: How Many Bricks for a Wall

Brick Calculator: How Many Bricks You Need for a Wall

A brick calculator estimates how many bricks a wall requires, based on its height, width and thickness. It accounts for the mortar joints between bricks, so the result matches how a bricklayer actually builds the wall rather than a simple area estimate.

Material costs make up a large share of a masonry project's budget. Ordering too few bricks means a delayed delivery and possible colour mismatch between batches. Ordering too many wastes money and storage space. A correct count avoids both problems.

How to Calculate Bricks Needed for a Wall

A brick wall is built from one or more skins (also called wythes) — a skin is a single brick-thick layer. A half-brick wall has one skin; a full-brick wall has two skins joined by a mortar collar joint.

Mortar sits between bricks along a course (the horizontal "bed joint") and between bricks within a course (the vertical "perpend joint"). It does not sit across the width of a single skin, because the brick itself already fills that space. The calculation works in two stages: how many bricks cover one square metre of wall face, and how many skins deep the wall is.

1. Wall area $\text{Wall Area} = \text{Height} \times \text{Width}$

2. Bricks per square metre of one skin $\text{Bricks per m}^2 = \frac{1}{(\text{Brick Length} + \text{Mortar}) \times (\text{Brick Height} + \text{Mortar})}$

3. Number of skins $\text{Skins} = \text{round}\left(\frac{\text{Wall Thickness} + \text{Mortar}}{\text{Brick Width} + \text{Mortar}}\right)$

4. Total bricks $\text{Bricks Needed} = \text{Skins} \times \text{ceil}(\text{Wall Area} \times \text{Bricks per m}^2)$

The result is rounded up, because a fraction of a brick cannot be ordered.

This calculator always uses the standard UK brick size (215 mm × 102.5 mm × 65 mm) with a 10 mm mortar joint; it does not accept custom brick dimensions. With those figures, one skin covers about 59.3 bricks per square metre, commonly rounded to 60 bricks per m². A two-skin (full-brick) wall needs about 120 bricks per m².

Standard Brick Dimensions by Region

Brick sizes vary by country. The table below is for reference only — this calculator's formula is fixed to the UK size.

Standard joint thickness ranges from 8 mm to 13 mm, with 10 mm the most common choice, per ASTM C270.

Worked Example

A garden boundary wall has these dimensions:

• Height: 1.8 m
• Length: 10 m
• Thickness: 0.215 m (a two-skin, "one-brick" wall)

Step by step:

1. Wall area = 1.8 × 10 = 18 m²
2. Bricks per m² of one skin = 1 ÷ (0.225 × 0.075) = 59.26
3. Bricks for one skin = ceil(18 × 59.26) = ceil(1,066.7) = 1,067
4. Skins = round(0.225 ÷ 0.1125) = round(2.0) = 2
5. Total bricks = 2 × 1,067 = 2,134 bricks

Adding a 10% waste allowance for a DIY project: 2,134 × 1.10 = 2,347.4, rounded up to 2,348 bricks. It is worth checking the supplier's pack size, since bricks are usually sold in fixed-quantity packs rather than single units.

Adding a Waste Allowance

Bricks break in transit, get cut wrong, or turn out defective. A calculator result is the minimum needed, not the amount to order. Typical allowances:

• 5% for an experienced bricklayer using a simple running bond
• 10% for a DIY project
• 15% for a complex pattern with many cuts, or a curved wall

$\text{Total with Waste} = \text{Bricks Needed} \times (1 + \text{Waste Factor})$

Accounting for Doors and Windows

Two approaches work. First, calculate the full wall, then subtract the opening: estimate the opening's area, convert it to a brick count using the same bricks-per-m² and skins figures, and subtract that from the total. Second, calculate each solid section of wall around the opening separately and add the results together. The second method is more reliable for walls with several openings.

Brick Bond and Extra Material

The bond — the pattern bricks are laid in — changes how many bricks a project needs beyond the basic count:

• Running bond: each brick overlaps the joint below it. Least waste, and the calculator's figure applies directly.
• English bond: alternating rows of headers (brick ends) and stretchers (brick faces). Needs roughly 20% more bricks than running bond, because headers expose less face area per brick used.
• Flemish bond: headers and stretchers alternate within each row. Needs roughly 15% more bricks, mainly for its decorative appearance.
• Herringbone: bricks laid at an angle, mostly for paving or panels. Angled cuts at every edge typically add 10–15% more bricks.

Frequently Asked Questions

How accurate is the brick calculator?

The arithmetic is exact for the standard UK brick size it uses. Real-world variation comes from brick size tolerances, mortar joint thickness and cutting waste, which is why a 5–15% allowance is standard practice on top of the raw count.

Does the calculator include mortar?

Yes. It treats the mortar joints between bricks (bed and perpend joints) as part of the spacing, but not as an extra layer across the thickness of a skin, since a brick already occupies that space.

How many bricks are in one square metre?

For a standard UK brick with a 10 mm joint: about 60 bricks per m² for a single-skin (half-brick) wall, and about 120 bricks per m² for a two-skin (full-brick) wall. This is a useful sanity check on any result.

What is a skin (wythe) in brickwork?

A skin is one brick-thick layer of a wall. A half-brick wall (102.5 mm) has one skin. A full-brick wall (215 mm) has two skins joined by a mortar collar joint.

Should extra bricks be ordered for waste?

Yes. Add 5% for straightforward work by an experienced bricklayer, 10% for most DIY projects, and 15% for complex patterns or curved walls. Ordering everything in one batch also avoids visible colour differences between manufacturing runs.

Can the calculator be used for non-UK brick sizes?

Not directly — it is fixed to the UK standard size (215 × 102.5 × 65 mm) with a 10 mm joint. For a different brick size, measure the actual brick, add the mortar joint thickness to each dimension, and recompute the bricks-per-m² figure by hand using the formula above.

References

1. ASTM C270-19 — Standard Specification for Mortar for Unit Masonry.
2. ASTM C216 — Standard Specification for Facing Brick.
3. Brick Development Association — UK brick sizing and technical guidance.
4. Brick Industry Association Technical Notes — masonry estimation guidance.