Brick to Block Converter — Convert Between Bricks and Blocks

In terms of wall area coverage, 6 standard bricks equal 1 standard block. A standard UK brick (215 x 102.5 x 65 mm) with 10 mm mortar joints covers approximately 0.017 m² of wall face, while a standard block (440 x 215 x 100 mm) covers approximately 0.101 m². This gives a ratio of roughly 6:1.

Blockwork is almost always cheaper for the inner leaf of a cavity wall. Blocks are larger so you need fewer units (10 per m² vs 60 bricks per m²), and the labour cost is significantly lower because a bricklayer can lay blocks much faster. However, facing bricks are needed for the outer leaf where appearance matters. A typical cavity wall uses blocks for the inner skin and facing bricks for the outer skin.

A standard UK brick is 215 mm long x 102.5 mm wide x 65 mm high. With 10 mm mortar joints, the working size (also called the coordinating size) becomes 225 x 112.5 x 75 mm. This gives 60 bricks per square metre of single-skin (half-brick) wall.

A standard UK concrete block is 440 mm long x 215 mm high x 100 mm thick. With 10 mm mortar joints, the coordinating size is 450 x 225 mm, giving 10 blocks per square metre. Blocks are also available in 140 mm and 215 mm thicknesses for thicker walls.

For half-brick (single skin) brickwork, allow approximately 0.03 m³ of mortar per m² of wall. This is a conservative UK quantity-surveying allowance covering bedding, perpends and waste — the net first-principles figure (60 bricks per m², 10 mm joints) is around 0.022 m³ per m², so order between the two depending on how much wastage you expect. (These are trade estimating rates, not quantities published in a British Standard; standards such as BS EN 998-2, PD 6697 and NHBC Chapter 6.1 govern the mortar mix and durability, not the volume per m².) For standard 100 mm blockwork, allow approximately 0.012 m³ of mortar per m². Blockwork uses less mortar because there are fewer joints — 10 blocks per m² versus 60 bricks per m². For a detailed cement and sand breakdown, use our dedicated Mortar Calculator, which uses the same 0.03 m³/m² half-brick and 0.012 m³/m² blockwork rates. Our Brick Calculator quotes the leaner 0.022 m³/m² net figure for the same wall, so allow for that difference if you cross-check the two.