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UK Brick Dimensions — Standard Sizes Reference

The standard UK brick has remained essentially the same size for over a century. Understanding brick dimensions, coordinating sizes, and the number of bricks per m² is essential for accurate estimating and ordering. This reference page covers everything you need to know.

Standard UK Brick Size

Length

215 mm

Width (depth)

102.5 mm

Height

65 mm

With a standard 10 mm mortar joint, the coordinating size (also called the working size) is 225 × 112.5 × 75 mm. This means one brick plus one mortar joint equals 225 mm long, 112.5 mm deep, and 75 mm high. The coordinating dimension system means bricks module perfectly: four courses of brickwork equal 300 mm in height.

Bricks Per m² by Bond Type

Bond TypeWall ThicknessBricks per m²Notes
Stretcher bond (half brick)102.5 mm60Most common: cavity wall outer leaf, garden walls
English bond (one brick)215 mm120Alternating courses of headers and stretchers
Flemish bond (one brick)215 mm120Headers and stretchers alternating within each course
English garden wall215 mm~90Three stretcher courses to one header course
One-and-a-half brick327.5 mm180Thick structural walls, retaining walls

All figures assume standard 10 mm mortar joints. Add 5–10% for waste and cuts.

Brick Types and Classifications

TypeStrengthWater absorptionUse
Common brick20+ N/mm²VariesInternal walls, hidden work
Facing brick20–60 N/mm²VariesExternal visible walls, aesthetic purposes
Engineering Class A≥70 N/mm²≤4.5%Below DPC, manholes, retaining walls
Engineering Class B≥50 N/mm²≤7%Below DPC, general engineering work

Mortar Quantities

For half-brick (stretcher bond) walls, you need approximately 0.02 m³ of mortar per m² of brickwork. For one-brick walls (English or Flemish bond), this doubles to around 0.04 m³ per m². A standard mortar mix for above-DPC brickwork is 1:5 or 1:6 (cement:sand). Below DPC, use a stronger 1:3 mix or add a waterproofer.

Calculate Your Brick Quantities

Use our free calculators for accurate brick and mortar estimates:

Brick dimensions conform to BS EN 771-1. Actual sizes may vary slightly between manufacturers. Imperial bricks (from older buildings) are typically 9″ × 4.5″ × 3″ (229 × 114 × 76 mm) and are slightly larger than modern metric bricks.