Standard UK brick Size & Weight

A standard UK brick is 215 x 102.5 x 65 mm and weighs roughly 2.5 to 3.5 kilograms depending on whether it is solid, perforated, or frogged. Add a 10 mm mortar joint and it works to a coordinating size of 225 x 112.5 x 75 mm, the module bricklayers design around.

This guide covers the exact UK brick dimensions, the coordinating size and why it matters, how the UK brick compares to a US brick and a concrete block, and how it sizes up against a phone and a ruler.

Quick Answer: How Big Is a UK Brick?

A UK “standard format” brick is 215 mm long, 102.5 mm wide, and 65 mm tall (work size, per BS EN 771). With mortar it coordinates to 225 x 112.5 x 75 mm. Weight is typically 2.5 – 3.5 kg.

UK Brick Dimensions at a Glance

• Work size: the physical brick, 215 x 102.5 x 65 mm
• Coordinating size: work size plus a 10 mm joint, 225 x 112.5 x 75 mm
• Four courses of brick plus joints = 300 mm of wall height (4 x 75 mm)
• A brick length (225 mm coordinating) equals a brick width plus a header joint, which is what lets bonds like Flemish and English work
• Weight: solid ~3.1 kg, perforated (holes) ~2.5 kg, frogged (indent) ~2.7 kg

What Does a UK Brick Look Like in Size?

A UK brick is a little shorter than a 30 cm ruler and about the length of a small hardback book. It is noticeably chunkier than a US brick, and heavier. A single course of bricks laid along a metre of wall uses about 4.4 bricks (at 225 mm coordinating).

6 Everyday Comparisons for a UK Brick

1. A 30 cm ruler (305 mm) is 90 mm longer than a UK brick.
2. A US modular brick (194 x 92 x 57 mm) is 21 mm shorter, 10.5 mm narrower, and 8 mm shorter in height.
3. An iPhone 15 (147.6 mm) is 67 mm shorter than the brick.
4. A UK concrete block (440 x 215 x 100 mm) is about twice a brick’s length and much taller; one block replaces about six bricks.
5. A loaf of bread (~280 mm) is 65 mm longer.
6. A house key (~55 mm) is a bit shorter than the brick’s 65 mm height.

UK Brick Size in Different Units

Work Size vs Coordinating Size

Bricklayers plan walls in coordinating dimensions because each brick takes up its own size plus one mortar joint. A UK brick is 215 mm long but occupies 225 mm of wall. So a wall “10 bricks long” is 10 x 225 = 2250 mm, and a wall “12 courses high” is 12 x 75 = 900 mm. The 65 mm brick height and 10 mm bed joint are chosen so that three bricks laid flat (with joints) equal one brick laid on end, which is what makes traditional bonds line up.

Common Mistakes When Comparing UK Brick Dimensions

1. Using the coordinating size as the physical brick. The brick is the 215 x 102.5 x 65 mm work size; 225 x 112.5 x 75 is with mortar.
2. Assuming UK and US bricks match. The UK brick is larger in all three dimensions.
3. Ignoring perforations. A perforated brick weighs about 0.5 – 0.6 kg less than a solid one of the same size.
4. Forgetting the joint in a course count. Four courses make 300 mm only with the 10 mm bed joints included.
5. Confusing “standard” with older imperial bricks. Pre-metrication UK bricks were about 9 x 4 3/8 x 3 in (229 x 111 x 76 mm), close but not identical, which matters for matching extensions to old houses.

Frequently Asked Questions

What is the standard UK brick size?

215 x 102.5 x 65 mm (work size); 225 x 112.5 x 75 mm with a mortar joint.

How much does a UK brick weigh?

Typically 2.5 – 3.5 kg, depending on whether it is solid, frogged, or perforated.

What is the coordinating size of a brick?

The work size plus one 10 mm mortar joint: 225 x 112.5 x 75 mm.

How many UK bricks are in a square metre of wall?

About 60 for a single-skin (half-brick) wall.

Is a UK brick bigger than a US brick?

Yes, in all three dimensions: 21 mm longer, 10.5 mm wider, and 8 mm taller than a US modular brick.

How high are four courses of brick?

300 mm, including the bed joints (4 x 75 mm coordinating).

Final Takeaway

A standard UK brick is 215 x 102.5 x 65 mm and about 2.5 – 3.5 kg, coordinating to 225 x 112.5 x 75 mm with a 10 mm joint. Walls are set out in coordinating sizes, four courses make 300 mm, and the UK brick is larger in every dimension than a US modular brick.