Calculate how many bricks you need for a wall with waste allowance
Whether you are building a garden wall, extending your home, or constructing a boundary wall, knowing exactly how many bricks to order is essential. Ordering too few means delays and potentially mismatched batches, while ordering too many wastes money and leaves you with surplus materials to store or dispose of. This brick calculator uses standard UK brick dimensions (215x102.5x65mm) with 10mm mortar joints to give you an accurate estimate of the number of bricks required for your project. It supports both stretcher bond (half-brick walls, commonly used for garden walls and internal partitions) and English bond (full-brick walls, used for structural and load-bearing applications). The calculator also includes a configurable waste allowance to account for cutting, breakages during delivery, and site wastage. In the UK, bricks are typically sold in packs of 400 or 500 on a pallet. Knowing the exact number you need helps you order the right number of packs and avoid expensive part-pallet surcharges from builders' merchants.
To calculate the number of bricks needed: 1. Measure and enter the wall length in metres. For walls with returns or corners, calculate each straight section separately and add the totals together. 2. Measure and enter the wall height in metres. Standard UK course height (brick plus mortar joint) is 75mm, so a 2-metre wall is approximately 27 courses. 3. Select the bond type. Choose stretcher bond for a half-brick wall (102.5mm thick) or English bond for a full-brick wall (215mm thick). Stretcher bond uses approximately 60 bricks per square metre, while English bond uses approximately 120. 4. Adjust the waste allowance. The default 10% is suitable for straightforward walls. Increase to 15% for walls with many cut bricks around piers, ends, or openings. Reduce to 5% for simple, straight runs with no cutting. 5. Review the results, which show the wall area, base brick count, total with waste, and estimated mortar weight. Use the mortar figure as a guide and cross-reference with the mortar calculator for exact bag counts.
The brick calculation is based on standard UK brick dimensions and coverage rates: Wall Area = Wall Length (m) x Wall Height (m) For stretcher bond (half-brick wall): Bricks per m2 = 60 (based on a standard UK brick at 215x102.5x65mm with 10mm mortar joints, laid in stretcher pattern). For English bond (full-brick wall): Bricks per m2 = 120 (double the stretcher rate, as the wall is twice as thick with alternating courses of stretchers and headers). Bricks Needed = ceiling(Wall Area x Bricks per m2) Bricks with Waste = ceiling(Bricks Needed x (1 + Waste % / 100)) For example, a 5m x 2m stretcher bond wall: area = 10 m2, bricks = 60 x 10 = 600, with 10% waste = 660 bricks. The mortar estimate uses approximately 1kg of mortar per brick, covering both the bed joint (horizontal) and perpend joint (vertical) at the standard 10mm thickness. This is a widely used industry rule of thumb endorsed by the Brick Development Association.
All measurements should be in metres. UK standard bricks comply with BS EN 771-1, with the most common size being 215x102.5x65mm (known as a "standard" or "metric" brick). If you are using non-standard bricks (such as London bricks or modular bricks), the coverage rates will differ. For walls with piers, openings, or decorative features, calculate the main wall area first, then add or subtract the relevant sections. Always check with your local Building Control office for structural requirements, particularly for walls over 1 metre in height or retaining walls.