Brick Calculator
Calculate the exact number of bricks and mortar bags needed for any wall or room.
By Syed Mubashir Ali · Last updated
Brick sizes you will actually meet
The UK standard brick is 215mm long, 102.5mm wide and 65mm high, laid with 10mm mortar joints. That gives you roughly 60 bricks per square metre for a half-brick wall: the figure most estimators carry in their heads. In Pakistan and India the common burnt clay brick is about 228 x 114 x 76mm, which works out differently, which is why the calculator has Pakistan and India presets alongside a custom size.
In the US, the modular brick (194 x 92 x 57mm) is the common unit, and quantities are often quoted per thousand. Whatever the local standard, the arithmetic is the same: face area divided by the area of one brick plus its share of mortar joint, multiplied by the number of skins. The calculator does this from whatever dimensions you enter.
Mistakes that cost real money
The expensive mistake is not a wrong count: it is a short delivery. Running out with 90% of a wall built means a second delivery charge, a delay while the bricklayer waits, and a visible batch change across the elevation. Ordering 5% over on a straightforward wall and 10% on anything with openings, piers or curves is cheap insurance.
The other mistake is forgetting the mortar. The calculator works out the cement and sand from the joints for your mix; enter their prices and they're added to the cost, because mortar on a large wall is not a rounding error. Frogged bricks laid frog up take noticeably more than solid ones.
How to Use Brick Calculator
- 1Choose your unit (metres or feet and inches) then enter the wall length and height.
- 2Pick a brick type from the presets, or choose custom and enter the brick dimensions in millimetres.
- 3Set the wall thickness: a half-brick single skin, a full-brick wall, or whatever your detail calls for.
- 4Add each door and window with 'Add a door' or 'Add a window' and adjust its size and number; they're taken off the wall area.
- 5Choose the mortar mix and the cement bag size you can buy, set the waste allowance (5% to start), and optionally enter prices for a cost.
- 6The results update as you type: bricks, cement bags, sand, the net wall area and the material cost. A shared link keeps every input.
- 7Check the result against pack sizes. Bricks usually come in packs of 300 to 500, so round your order up to whole packs. The calculator gives you the exact figure; your supplier sells in packs.
Frequently Asked Questions
Is wastage included?
Yes: 5% to start, and you can change it. That covers ordinary cuts and breakages on a straightforward wall; for a job with lots of cutting, openings or returns, 10% is closer to reality. The same allowance is added to the mortar.
How is the mortar estimate worked out?
By volume. The wall's volume less the bricks' own volume is the wet mortar in the joints. Loose cement and sand take up about a third more room than the mortar they make, so the dry volume is 1.33 times the wet, split in your mix ratio, with cement at 1,440 kg per cubic metre and divided into the bag size you buy. As a check, a cubic metre of modular brickwork at 1:6 works out at about 1.26 bags (50 kg) of cement and 0.26 m³ of sand, the usual textbook figure. Frogged bricks laid frog up take more, because the frog is filled.
Does wall thickness change the count?
Significantly: a full-brick wall uses roughly twice the bricks of a half-brick skin over the same face area. Setting it correctly matters more than the brick dimensions do.
What if my bricks are a non-standard size?
Choose Custom and enter the length, height and width in millimetres. The bricks-per-square-metre figure recalculates from your dimensions, including the mortar joint allowance.
Should I deduct openings?
Yes, for anything bigger than a small window. Add each door and window and the calculator takes them off the wall area; a standard door is about 0.9 × 2.1 m (1.9 m²), roughly 110 UK bricks in a half-brick wall.
How many bricks are in a pack?
Typically 300 to 500, depending on the supplier and brick type. Machine-made stock bricks often come in 500s; handmade or facing bricks in smaller packs. Always confirm with your supplier before ordering, because the calculator gives you an exact count and you will need to round up.
What mortar mix should I use?
For ordinary brickwork above ground, a 1:4 cement-to-sand mix (with a plasticiser) is the common choice. Below ground or in exposed positions, go stronger at 1:3; 1:6 is common for internal, lightly loaded walls in Pakistan and India. Choose the mix and the calculator splits the cement and sand to match. Do not guess at this on structural work: the mix affects strength, and your engineer or bricklayer will specify it.
Does it work for a garden wall?
Yes, and garden walls are where people most often under-order. They have two faces to look at, more cutting at the ends and piers, and no wastage allowance survives contact with a curved wall. Set the waste allowance to 10% for anything with piers or curves.
About Brick Calculator
The Brick Calculator estimates how many bricks, how much cement and how much sand a wall needs, from its dimensions, the doors and windows in it, the brick size and the wall thickness, and what they'll cost at your prices. It runs entirely in your browser: nothing you enter is sent anywhere.
Two inputs dominate the answer. Wall thickness roughly doubles the count between a half-brick skin and a full-brick wall, and brick size changes the bricks per square metre, which is why the custom option takes dimensions in millimetres rather than assuming a standard.
The waste allowance starts at 5% and is yours to change. That is a reasonable figure for a plain wall; a job with many openings, returns or angled cuts generates more waste, and 10% is cheaper than a second delivery for forty bricks.
Cement and sand come from the volume of the joints, for the mix ratio and bag size you choose, rather than a bags-per-brick rule of thumb. Both unit systems are supported, including feet and inches, and the brick, bag size and mix start on what's usual where you are.
Order timing matters as much as the count. Bricks from different batches can vary slightly in colour, which shows on a large elevation. Order the full quantity in one delivery where you can, and store packs off the ground on battens, covered, so a rainstorm does not turn the bottom course into a cleaning job.