How many bricks are in a square metre?

For a standard 230 x 76 mm Australian house brick laid with a 10 mm mortar joint, about 48.5 bricks per square metre. Bigger bricks lay fewer per square metre; smaller or 'split' faces lay more.

How much wastage should I allow?

Five per cent is a fair default for a straight, plain wall. Push it to 10% when there are lots of small returns, feature bonds, cuts around openings, or if this is your first brick job.

Does the calculator include mortar?

Yes, when you use the standard 230 x 76 brick. It shows the number of 20 kg premixed mortar bags at the published rate of one bag per 20 bricks. If you site-mix from cement and sand, ask your supplier for their yield.

What about double brick or cavity walls?

Tick 'double brick' and the calculator counts both leaves. Openings still deduct from each leaf. It does not include ties, weep holes or damp-proof course lengths.

Is this figure a quote?

No, it is an estimate to help you plan and price. Always confirm the final quantity with your bricklayer or supplier before you order.

Free calculator

Brick calculator

For a standard 230 x 76 mm brick with a 10 mm mortar joint you need about 48.5 bricks per square metre of wall. Multiply that by the net wall area (after taking out doors and windows), then add wastage.

Your job

Wall size

Length

Height

Doors and windows

Brick

230 x 76 mm face

Mortar joint

Colour

Allowances

Wastage allowance5%

5% covers cuts and breakages on a straight wall. Go to 10% if there are lots of openings, corners or a feature bond.

Optional

Bricks per pallet

Your price per brick

Ask your supplier for both. Greyed numbers are examples only and are never used in your result.

Drag the orange handles to resize the wall

Bricks to order

733

Includes 5% wastage, rounded up

Net wall area

14.40m²

No openings deducted

Mortar

37x 20 kg bags

Premixed mortar for standard bricks

The working, with your numbers

1. Wall area6.00 m x 2.40 m= 14.40 m²
2. Less openings14.40 - 0.00= 14.40 m²
3. Bricks per m²1,000,000 / ((230 + 10) x (76 + 10))= 48.45
4. Bricks14.40 x 48.45= 697.7
5. Add wastage, round up697.7 x 1.05= 733 bricks

Typed those measurements in by hand?MetreMate measures them straight off your PDF plans. Free to start.

The formula, in plain words

1Bricks per square metre = 1,000,000 divided by ((brick length in mm plus joint) times (brick height in mm plus joint)).
2Wall area = length times height, in square metres.
3Net area = wall area minus the area of every door and window.
4Bricks needed = net area times bricks per square metre. Double if the wall is double brick, then multiply by (1 plus wastage) and round up.
5Premixed mortar = one 20 kg bag per 20 standard bricks laid.

Worked example

A 6 m long, 2.4 m high single-skin wall in standard bricks (230 x 76 mm) with a 10 mm joint, one door (0.82 x 2.04 m) and a 5% wastage allowance.

1.Wall area: 6 x 2.4 = 14.4 m².
2.Door area: 0.82 x 2.04 = 1.67 m². Net wall = 14.4 - 1.67 = 12.73 m².
3.Bricks per m²: 1,000,000 / (240 x 86) = 48.45.
4.Bricks: 12.73 x 48.45 = 616.7. Add 5% and round up = 648 bricks.
5.Mortar: 648 / 20 = 33 x 20 kg bags of premixed mortar (rounded up).

Answer: About 648 bricks and 33 x 20 kg bags of premixed mortar.

How to measure it

Measure the wall in metres. Length times height gives the gross face area.
List every door and window opening. Width times height times how many of that size.
Pick your brick size and joint. Most Australian house bricks are 230 x 76 mm with a 10 mm bed and perp joint.
If the wall is a double-brick cavity wall, tick 'double brick'. That doubles the bricks and roughly doubles the mortar.

Where the numbers come from

Every default in the calculator is a number a supplier or manufacturer publishes. We list the source next to it so you can check.

What	Value	Source
Standard brick (230 x 110 x 76 mm) laid with a 10 mm joint	48.5 bricks per m²	PGH Bricks brick calculator (checked 2026-09-21)
Standard mortar joint	10 mm	Cement Australia mortar calculator (states a standard 10 mm joint) (checked 2026-09-21)
Standard bricks laid per 20 kg bag of premixed mortar	20 bricks per 20 kg bag	Cement Australia mortar calculator (checked 2026-09-21)

Manufacturers named here are the source of the number, not a recommendation. Confirm quantities with your supplier.

Frequently asked questions

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