Brick Calculator
Brick calculator — enter your wall length and height to get the number of bricks you need, with a waste allowance and an approximate mortar quantity. Adjust the bricks-per-square-metre for single or double skin and your brick size. Runs in your browser.
Brick Calculator
How to Use the Brick Calculator
Measure the wall
Enter the length and height in metres.
Set bricks per m²
60 for single skin, 120 for double.
Add waste
5–10% for breakages and cuts.
Read the count
See bricks and an approximate mortar quantity.
Bricks by the Square Metre
Brickwork is estimated by area, but the figure that turns area into a brick count — bricks per square metre — is the one people most often get wrong. For a standard metric brick, measuring 215 by 65 millimetres on the face and laid with a 10-millimetre mortar joint, roughly 60 bricks cover one square metre of a single-skin (half-brick) wall. A double-skin or cavity wall has two leaves, so it needs about 120 per square metre. This calculator multiplies your wall’s length by its height, applies the bricks-per-square-metre figure you choose, and adds a waste allowance to give the number you should actually order.
Choosing the right per-square-metre figure is the key decision. Use 60 for the single-skin walls common in garden walls and the outer leaf of a house, and 120 for a one-brick wall. If you are working with a non-standard brick or a concrete block, adjust the figure to match — suppliers quote a coverage for each product. The waste allowance then protects you against the inevitable losses: bricks chip and crack in delivery and handling, and cutting at corners, openings and the ends of courses leaves offcuts that cannot always be reused. Five to ten percent is standard, leaning higher for jobs with piers, arches or decorative bonds.
The tool also offers an approximate mortar quantity, because brick orders and mortar orders go together. As a rough guide, a 25-kilogram bag of ready-mix mortar lays around a square metre of single-skin brickwork with standard joints, but real usage swings with joint thickness, brick type — frogged bricks, laid frog-up so the indent fills with mortar, use more — and how wet you mix it. Treat the mortar figure as a planning estimate and buy a little extra. Two final habits make the difference between a tidy wall and a patchy one: order all your bricks plus the waste in a single delivery from the same batch, since fired-clay colour varies between batches, and remember that cold or wet weather can stop mortar curing properly. For decorative bonds, curves and openings, a bricklayer’s eye will refine the count — but for a straight wall, the number here is a confident order. As always, everything is calculated in your browser, so your measurements stay private.
About 60 bricks per square metre for a single skin, 120 for a double — get that one figure right and the rest is just area.
10 Facts About Brickwork
A single-skin wall needs about 60 bricks/m².
A double-skin (cavity) wall needs about 120/m².
Standard UK brick face is 215 × 65 mm with a 10 mm joint.
Always order 5–10% extra for breakages and cuts.
A 25 kg bag of mortar lays roughly a square metre of single skin.
Match the brick batch for consistent colour.
Mortar joints are typically 10 mm thick.
Frogged bricks are laid frog up to fill with mortar.
Cold weather can stop mortar curing properly.
This calculator runs in your browser — nothing is uploaded.
Frequently Asked Questions
- Multiply the wall length by its height for the area, multiply by the number of bricks per square metre, then add a waste allowance. For a standard single-skin wall using metric bricks, about 60 bricks cover a square metre including the mortar joints. This calculator does the full sum and adds your chosen waste percentage.
- It is how many brick faces fit in a square metre of wall once the mortar joints are included. For a standard metric brick (215 by 65 millimetres) laid in a single skin with 10-millimetre joints, that works out to about 60 per square metre. A double-skin or cavity wall is effectively two leaves, so roughly 120 per square metre.
- Use 60 for a half-brick (single-skin) wall, the most common for garden walls and the outer leaf of a house. Use 120 for a one-brick (double-skin) wall. If you are using a non-standard brick or block size, adjust the figure to match your brick’s coverage, which suppliers usually quote.
- Five to ten percent is standard. Bricks get damaged in delivery and handling, and cuts at corners, openings and the ends of courses produce unusable offcuts. For a job with lots of cuts — piers, arches, decorative bonds — lean toward the higher end. Rounding up is always safer than running short mid-course.
- As a rough guide, a 25-kilogram bag of ready-mix mortar lays around one square metre of single-skin brickwork with standard joints, so the calculator estimates bags from the wall area. Actual usage depends on joint thickness, brick type (frogged bricks use more), and your mixing consistency, so treat the mortar figure as approximate and buy a little extra.
- The frog is the indentation in the top face of many bricks. Bricks are normally laid frog-up so the indentation fills with mortar, which slightly increases mortar usage compared with solid bricks. It does not change the brick count, but it is one reason the mortar estimate is a guide rather than an exact figure.
- It calculates the gross wall area. For a wall with significant openings, you can subtract the opening area from the wall area before entering it, but many builders keep the gross figure because cutting around openings generates waste that roughly offsets the saving. The waste allowance helps cover this either way.
- Bricks are fired in batches and colour can vary noticeably between them, especially for some clay bricks. Ordering all your bricks — plus the waste allowance — in one delivery from the same batch keeps the wall a consistent colour. Topping up later can leave a visible band of mismatched brick.
- It is a reliable estimate for a straightforward straight wall. Decorative bonds, piers, arches, curved walls and heavy cutting all change the real count, and mortar usage varies with technique. Use the figure to order confidently, keep the waste allowance, and consult a bricklayer for complex work.
- Completely free, with no account or limit. It works offline once the page has loaded and collects no data.
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