Calculate the number of bricks needed for a wall based on its dimensions, brick size, and mortar joint thickness.
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This tool calculates the number of bricks needed to build a wall, based on the wall's dimensions (length, height, and thickness), the size of the brick used (length, height, and width), and the thickness of the mortar joint between bricks. Brick sizes actually vary between countries and manufacturers, so the tool lets you adjust the default size (20×10×10 cm) to match the bricks available to you locally, since using an incorrect brick size assumption is one of the most common sources of estimation error in masonry planning. The method works by dividing the full wall volume by the "actual brick volume including the surrounding mortar" (not just the dry brick volume alone), because mortar occupies real space between each pair of adjacent bricks — typically 10mm on each face — and must be accounted for to get an accurate final count, since ignoring mortar thickness alone can undercount bricks needed by 10% or more on a large wall. A standard 5% wastage allowance is also added on top of that to cover cutting and breakage at corners, openings, and edges, which is standard practice recommended in masonry estimating guides.
It's tempting to estimate bricks needed for a wall with a simple calculation: wall area divided by one brick's face area. This shortcut, while intuitive, systematically undercounts the actual bricks required, because it ignores something that occupies real physical space in every course of brickwork — the mortar joint between each pair of bricks.
A typical mortar joint runs about 10mm thick on both the horizontal and vertical faces where bricks meet. That might sound negligible for a single joint, but multiplied across every brick in a wall, it adds up to a meaningful amount of extra volume that mortar occupies instead of brick — space that a naive area-based calculation completely misses.
The correct engineering approach treats each brick as occupying not just its own physical volume, but an 'effective' volume that includes its share of the surrounding mortar — essentially, the brick plus half a mortar joint on each side it touches. Dividing the total wall volume by this effective brick-plus-mortar volume, rather than the bare brick volume, gives a genuinely accurate count.
This distinction matters most on larger walls, where the cumulative effect compounds: ignoring mortar thickness on a small garden wall might introduce a negligible error, but on a full house exterior wall, the same oversight can mean ordering 5-10% too few bricks, leading to a mid-project supply run and potential batch-color mismatches between the original and supplementary brick order.
On top of the mortar-adjusted volume calculation, a separate wastage allowance — typically 5% — is standard practice in masonry estimating to cover bricks broken during handling, cut pieces at corners and around window and door openings, and general material loss during construction. Combining both the mortar-volume correction and the wastage allowance gives a total that closely matches what experienced masons actually order for a project of a given size.
Mortar occupies real space between bricks. Ignoring it would overestimate how many bricks fit into the wall volume, so the calculator adds the joint thickness to each brick dimension before dividing.
Yes, brick sizes vary significantly by country and manufacturer. Simply change the brick length, height, and width fields to match your local bricks before calculating.
No, this gives the total bricks for a solid wall of the given dimensions. Subtract the area of any openings from your wall dimensions first, or calculate them separately and deduct the difference.