Brick sizes - Designing Buildings
The standard co-ordinating size for brickwork is 225 mm x 112.5 mm x 75 mm (length x depth x height). This includes 10 mm mortar joints, and so the standard size for a brick itself is 215 mm x 102.5 mm x 65 mm (length x depth x height). This gives a ratio of 3:2:1, meaning that: