Construction & trade New Zealand
Brick Calculator New Zealand
Ordering the right number of bricks avoids a second delivery in a different batch, which can differ in colour. Enter the wall length and height, the openings and the brick face size to get the number to order, allowing for the mortar joint and breakage.
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Doors, windows and gaps.
Bricks to order
—Wall area after openings
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Bricks per m²
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Bricks before wastage
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Estimated brick cost
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The working
An estimate for ordering. General information and estimates only, not professional advice. Brick walls are structural and subject to the Building Code, so confirm quantities and design with a builder or supplier.
How many bricks do I need for a wall?
Divide the wall area by the area of one brick face including its mortar joint, then add an allowance for breakage. A 10 m by 2.4 m wall with 4 m² of openings is 20.0 m². A 230 × 76 mm brick with 10 mm joints gives about 48 bricks per square metre, so you need roughly 1,018 bricks with 5% extra.
Ordering and batches
Bricks vary slightly in colour from batch to batch, so order the whole job at once and mix packs when you lay them. Bricks are sold in packs on a pallet, so round up to a full pack and ask the supplier whether they take back unopened packs. Keep a few spare for repairs later.
Design and the Building Code
Brick veneer walls must meet the Building Code, which covers fixings, flashing, cavity drainage and earthquake resistance. Freestanding garden walls over a certain height may need a building consent. A designer or builder should confirm the details; this calculator only counts bricks.
To estimate mortar or concrete for a footing, use the concrete calculator.
How this is calculated
The rule, step by step, so you can check any figure by hand.
net wall area = length × height − openingsbricks per m² = 1,000,000 ÷ ((brick length + joint) × (brick height + joint)), in millimetresbricks needed = area × bricks per m²order = bricks needed × (1 + wastage ÷ 100), rounded up
The mortar joint is part of the coverage: a brick with a 10 mm joint covers a face of its own size plus the joint on two sides, which is why 76 mm bricks cover about 86 mm of wall height. Changing the joint thickness moves the count by several bricks per square metre, so use the thickness your bricklayer will work to.
In New Zealand brick is mostly used as a veneer over a timber frame, rather than as a double-skin wall, because masonry must be designed for earthquakes. A veneer is one brick thick, so the single-skin count applies. Corners, cut bricks and reveals add to the count, so a 5% allowance is a minimum.
A worked example
A 10 m by 2.4 m wall with 4 m² of openings, 230 × 76 mm bricks, 10 mm joints, 5% wastage.
- Net area20.0 m²
- Face with joint240 × 86 mm
- Bricks per m²48.4
- Before wastage969
- To order1,018
About 1,018 bricks.
Order a little over so the batches match.
Mortar and extras
Mortar adds to the cost: a rough guide is about a bag of cement for every 40 to 50 bricks, plus sand. Also allow for wall ties, flashings, lintels over openings and a damp-proof course. These are not in this count.
What it leaves out
Bond patterns, corners, special shapes and curved walls are not modelled. The count assumes a straight stretcher-bond wall.
What this calculator does not do
- Straight single-skin wall
- Face sizes as you set them
- Corners and special shapes extra
- An estimate for ordering
Common questions
How many bricks are there in a square metre?
About 48 for a 230 × 76 mm brick with 10 mm joints.
How much extra should I order?
At least 5% for breakage and cuts.
Do I deduct windows and doors?
Yes, enter their area as openings.
Are brick walls common in New Zealand?
Mostly as a veneer on a timber frame.
Does the mortar joint matter?
Yes, it changes how many bricks fit in a square metre.
Where these numbers come from
- Wolfram MathWorld — area Fixed formulas for area and coverage; nothing to go out of date
- Building Performance — MBIE Guidance on building work and materials in New Zealand
Method last reviewed 2026-10-28 This calculator uses fixed rules rather than rates that change, and its method is re-checked against the sources above at least once a year. Out of date? Tell us and we will fix it.
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