Free UK construction calculators Metric and imperial 2026 UK prices
Work out how many bricks you need for a wall, plus the mortar, cement and building sand to lay them. It handles straight walls, walls with windows and doors, gable ends and known areas, in half-brick, one-brick or thicker walls, using standard UK bricks or your own brick size.
Bricks To Order
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Check the measurements above. The result updates once they look right.
| Item | Quantity | How It Is Sold |
|---|
Mortar figures allow for frogs, droppings and normal waste. A bulk bag of sand is taken as about 850 kg.
| Thickness | Per m² | To Order |
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Uses your brick size, joint and waste. Your choice is highlighted.
This brick calculator gives you a brick count, the number of packs and the mortar materials for a wall in one go. You can work in metres or feet, and the result updates as you type.
Open "Mortar Mix, Packs And Price" to change the mortar ratio, the pack size your supplier uses, or to add a price per 1,000 bricks. Then download the PDF to take to the builders' merchant.
With standard UK bricks and 10 mm mortar joints, each brick takes up a space of 225 mm × 75 mm on the face of the wall. That works out at 59.3 bricks per square metre, which builders round to 60. A thicker wall simply multiplies that figure.
| Wall thickness | Bricks per m² | Bricks per 10 m² | Mortar per 10 m² |
|---|---|---|---|
| Half brick (102.5 mm) | 59.3 (about 60) | 593 | 0.23 m³ |
| One brick (215 mm) | 118.5 (about 120) | 1,185 | 0.59 m³ |
| One and a half brick (327.5 mm) | 177.8 (about 180) | 1,778 | 0.95 m³ |
These figures are before waste. They also assume you are using the standard brick size. A taller brick, such as an older imperial brick, means fewer bricks per square metre.
The standard UK brick has been 215 × 102.5 × 65 mm for decades. This is called the work size. Add a 10 mm joint to the length and height, and you get the coordinating size of 225 × 112.5 × 75 mm, which is what designers use to set out walls so that whole bricks fit.
| Brick | Typical size | Notes |
|---|---|---|
| Standard UK brick | 215 × 102.5 × 65 mm | Used for almost all new building |
| Older imperial bricks | About 9 × 4¼ × 2⅝ to 2⅞ in | Common in pre-1970s houses; sizes vary |
| Reclaimed bricks | Varies | Measure several, as old bricks are rarely uniform |
| Engineering bricks | 215 × 102.5 × 65 mm | Dense and strong; often used below the damp-proof course |
| Brick slips | About 215 × 65 mm face, 15–25 mm thick | Cladding only, not for building walls |
When you are extending an older house, it is worth measuring the existing bricks. If they are taller than 65 mm, enter their size under Custom Size so the count matches the courses you will be lining up with. The Brick Development Association has more guidance on brick types.
The calculator works out the brickwork area, then how many bricks fit in each square metre, then adds waste.
For a straight wall, the area is length × height. For a wall with openings, the area of each window and door is taken off. For a gable end, the rectangle up to the eaves is added to the triangle above it, which is half the width times the extra height to the ridge.
The mortar is the space in the wall that is not brick: the bed joints, the joints between brick ends and, in thicker walls, the joint between the skins. The calculator adds 30% on top of that to cover filling the frogs, mortar dropped while laying and normal waste. For a half-brick wall this comes to about 0.023 m³ of mortar per square metre, close to the 0.022 m³ trade rate used across the UK.
These examples use standard UK bricks, 10 mm joints and a 4:1 mortar mix.
The area is 24 m². At 59.3 bricks per m², the wall needs 1,422 bricks. With 5% waste, order 1,494 bricks, which is three packs of 500. The mortar comes to 0.55 m³: seven bags of cement and about 0.88 tonnes of building sand.
A garden wall 6 m long and 900 mm high, built one brick thick, has 5.4 m² of face. Two skins need 640 bricks, or 672 bricks with 5% waste. Mortar is about 0.32 m³, so four bags of cement and half a tonne of sand.
An 8 m × 2.5 m wall has 20 m² of face. Two windows of 1.2 m × 1.2 m and a door of 0.9 m × 2.1 m take off 4.77 m², leaving 15.23 m². That needs 903 bricks, or 993 bricks with 10% waste for the cuts round the openings.
A gable 6 m wide, 2.5 m to the eaves and 4.5 m to the ridge has 15 m² below the eaves and 6 m² in the triangle, 21 m² in total. That is 1,244 bricks, or 1,369 bricks with 10% waste, because every course in the gable is cut at both ends.
The pattern bricks are laid in is called the bond. It ties the bricks together so the wall acts as one piece.
Freestanding walls need to be thick enough for their height and how exposed they are to wind. Taller garden walls are usually one brick thick or have piers at intervals. If you are building a boundary wall over about a metre high, or any retaining wall, get advice before you start.
Mortar for bricklaying is usually mixed on site from soft building sand and cement, often with a plasticiser to make it easier to work. The calculator turns the mortar volume into bags of cement and tonnes of sand, using about 1.6 tonnes of sand per m³ of mortar.
| Mix (sand : cement) | Mortar | Cement (25 kg bags) | Building sand |
|---|---|---|---|
| 3:1 | 0.39 m³ | 7 | 0.62 t |
| 4:1 | 0.39 m³ | 5 | 0.62 t |
| 5:1 | 0.39 m³ | 4 | 0.62 t |
| 6:1 | 0.39 m³ | 4 | 0.62 t |
Many bricklayers use the rule of thumb of one tonne of sand and six or seven bags of cement for every 1,000 bricks. That is more generous than the figures above, and it leaves spare for pointing and the odd extra batch. Building sand is commonly sold in bulk bags of around 850 kg, and in smaller bags for little jobs.
If you would rather not mix your own, ready-mixed mortar in bags or silo mortar delivered to site saves time and keeps the colour consistent.
| Mix (sand : cement) | Strength | Typical use |
|---|---|---|
| 3:1 | Strong | Below the damp-proof course, very exposed walls, engineering bricks |
| 4:1 | General | Most external brickwork and garden walls |
| 5:1 | Standard | General brickwork in sheltered spots |
| 6:1 | Soft | Internal walls and softer bricks |
Stronger is not always better. Mortar should be a little weaker than the bricks, so that any movement cracks the joints rather than the bricks themselves. Soft, older bricks are often laid in lime mortar for that reason. If you are matching existing brickwork, try to match its mortar colour and strength too.
| Waste | When to use it |
|---|---|
| 5% | Straight walls with few cuts, new bricks from one batch |
| 10% | Walls with windows, doors, piers or gable ends |
| 15% | Reclaimed bricks, or walls with many angles and cuts |
Waste covers broken bricks, cuts at the ends of courses and round openings, and a few spares for repairs later. Keeping a handful of spare bricks from the same batch is useful if one ever needs replacing.
Speed depends on the wall, the weather and how much cutting there is. An experienced bricklayer on a plain, straight wall can lay several hundred bricks a day, usually with a labourer mixing mortar and moving bricks. Walls with lots of openings, corners or decorative work go much more slowly. A first-time DIY bricklayer should expect to lay far fewer, and should focus on keeping each course level and plumb rather than on speed.
Do not lay bricks when frost is forecast, and protect fresh work from heavy rain. Check the Met Office forecast before you start.
About 60 standard UK bricks for a half-brick wall with 10 mm joints. The exact figure is 59.3. A one-brick wall needs about 120 per m².
It depends on the height. A 10 m wall 1 m high in half-brick needs about 593 bricks, or 623 with 5% waste. At 2 m high it needs about 1,245 with waste.
Pack sizes vary by manufacturer and product, but 400 to 500 bricks per pack is common. Check with your supplier and enter their pack size in the calculator.
A standard UK brick is 215 mm long, 102.5 mm wide and 65 mm high. With a 10 mm joint, it takes up 225 × 75 mm on the face of the wall.
For a half-brick wall, about 0.39 m³ of mortar: roughly 0.62 tonnes of building sand and five 25 kg bags of cement at a 4:1 mix. Many builders allow a tonne of sand and six or seven bags for a little spare.
A 4:1 sand to cement mix with plasticiser suits most garden walls. Use a stronger 3:1 mix below ground or in very exposed spots.
Allow 5% for simple straight walls, 10% for walls with openings or gables, and 15% for reclaimed bricks.
A half-brick wall is fine for low walls, planters and the outer leaf of a cavity wall. Taller freestanding walls usually need to be one brick thick or have piers. Get advice for anything tall or retaining soil.
Add the rectangle up to the eaves to the triangle above it. The triangle is half the wall width times the extra height to the ridge. Then multiply by about 60 bricks per m² for each skin.
Yes. Choose Custom Size and enter the length, width and height of one of your bricks. The calculator works out how many fit per square metre.
On a plain straight wall, an experienced bricklayer can usually lay several hundred bricks a day with a labourer. Walls with openings, corners or detailing take longer.
Plan the rest of your wall and the project around it.
Figures use the standard UK brick of 215 × 102.5 × 65 mm with 10 mm joints. Mortar is the joint volume plus 30% for frogs and waste, with about 1.6 tonnes of sand per m³ and 12.5 bags of cement per m³ at 4:1. Pack sizes and brick dimensions vary by product, so check with your supplier. Reviewed November 2026.