Brick Size Table
| Country | Metric (mm) | Imperial (in) | Ratio L:W:H |
|---|---|---|---|
| Australia | 230 × 110 × 76 | 9.1 × 4.3 × 3.0 | 3 : 1.4 : 1 |
| China | 240 × 155 × 53 | 9.4 × 6.1 × 2.1 | 4.5 : 2.9 : 1 |
| Denmark | 228 × 108 × 54 | 9.0 × 4.3 × 2.1 | 4.3 : 2 : 1 |
| Germany | 240 × 115 × 71 | 9.4 × 4.5 × 2.8 | 3.4 : 1.6 : 1 |
| India | 228 × 107 × 69 | 9.0 × 4.2 × 2.7 | 3.3 : 1.6 : 1 |
| Japan | 210 × 100 × 60 | 8.3 × 3.9 × 2.4 | 3.5 : 1.6 : 1 |
| Romania | 240 × 115 × 63 | 9.4 × 4.5 × 2.5 | 3.8 : 1.8 : 1 |
| Russia | 250 × 120 × 65 | 9.8 × 4.7 × 2.6 | 3.8 : 1.8 : 1 |
| South Africa | 222 × 106 × 73 | 8.7 × 4.2 × 2.9 | 3 : 1.4 : 1 |
| Sweden | 250 × 120 × 62 | 9.8 × 4.7 × 2.4 | 4.1 : 2 : 1 |
| United Kingdom | 215 × 102.5 × 65 | 8.5 × 4.0 × 2.6 | 3.3 : 1.5 : 1 |
| United States (modular) | 194 × 92 × 57 | 7.6 × 3.6 × 2.2 | 3.5 : 1.6 : 1 |
Brick is local law, like wire colors and plug sockets: every brickmaking country standardized its own face brick, and the differences are not rounding errors - the Russian standard runs 250 mm long while the Japanese sits at 210, and the American modular brick is a full centimeter slimmer than the British one. The table lines up twelve national standards in millimeters, inches and proportion, so imported drawings, renovation estimates and cross-border comparisons start from real numbers instead of the mythical one-size brick.
The mortar joint is what turns those odd numbers into clean arithmetic. The UK brick (215 x 102.5 x 65 mm) plus its 10 mm joint gives a nominal 225 x 112.5 x 75 - a tidy 6:3:2 module that yields about 60 bricks per square metre of single-skin wall. The US modular brick (194 x 92 x 57 mm) plus a 3/8 inch joint gives a nominal 8 x 4 x 2 2/3 inches, and that 2:1 face has a built-in trick: walls turn corners in half running bond with no cut bricks, and one soldier course stands exactly as tall as three running courses or one concrete-block course.
How to use
- Estimate wall quantities from nominal sizes, never actual ones: the joint is part of the module, so UK walls cost about 60 bricks per square metre single skin and US modular walls about 7 per square foot - the table gives you the nominal pair for the arithmetic.
- Plan bond around the ratio column: a 2:1 face (US modular) lays half bond through corners without cutting, while other proportions dictate where headers and closers fall - checking the ratio first beats discovering it mid-course.
- Spec the material by exposure and load: solid clay runs about 2,000 kg/m3, and aerated autoclaved concrete drops to 450-850 kg/m3 with far better insulation - the density spread is the insulation-versus-strength dial.
Frequently asked questions
Why do brick sizes differ from country to country?
Climate wrote the first draft. A bigger brick means a thicker, more thermally massive wall, so cold countries standardized long bricks - the Russian 250 mm against the Japanese 210 mm - while warm regions saved clay and labor with smaller units. The cautionary tale is the Green Gate in Gdansk: built in 1571 from imported Dutch brick that was sized for a milder climate, it was notorious for centuries as a cold, drafty residence. There is also law in the mix - England regulated the common brick by statute from 1625. Modern walls ended the thermal argument (specialized insulation does that work now), so today the differences survive as pure national convention - and as the reason imported brick drawings never quite fit local walls.
How many bricks do I need per square metre or square foot?
Divide by the nominal face, never the brick face. UK: nominal 225 x 75 mm per brick gives 1000/225 x 1000/75 = 4.44 x 13.33 = about 59, quoted everywhere as 60 bricks per square metre of single-skin (half-brick) wall; a double-skin cavity wall doubles it, and piers, wastage and breaks add 5-10 percent on top. US modular: nominal 8 x 2 2/3 inches is 21.3 square inches, so 144/21.3 = about 6.75, quoted as 7 per square foot. The joint is doing half the work in those numbers - which is why counting from actual brick size underestimates by roughly a third. For a quick site check: one stretch of a square metre laid dry is the fastest yardstick a waller can carry.
What is the frog in a brick - and does it go up or down?
The frog is the indentation pressed into one of the long faces, named either for the amphibian or for the tool that makes it; modern frogs are plastic, older ones were wood. It buys three things at once: less clay per brick, a lighter unit, and a keying recess that locks mortar into the wall. Solid bricks are defined as under 25 percent perforations by volume (frogs included), perforated bricks run patterned holes up to that line, cellular and hollow bricks go beyond it with one closed face for the hollow types. Laying practice puts the frog up so the mortar fills the recess and keys the courses together - a frog laid down leaves a void in the bed joint, which is exactly where a wall freezes and spalls first.
Brick vs block - where is the line?
Size first, material second. Blocks play a much bigger game: standard coordinating faces run 400 x 200 up to 600 x 225 mm with depths from 60 to 250 mm, versus the roughly 225 x 112.5 mm UK brick module - one block course replaces three brick courses, which is why blockwork rises faster and why the US modular soldier course matches one CMU course exactly. Materially, blocks are lighter per volume (often concrete or AAC), and AAC even as a solid unit drops to 450-850 kg/m3 against solid clay at about 2,000 kg/m3, trading density - the strength-and-mass story - for insulation. The trade rule of thumb: brick for the facing, weather line and looks; block for the structure and speed behind it.