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Brick & Block Calculator

Number of bricks or blocks, bags of mortar and sand for a wall from area and bond pattern. Free construction calculator for brick & block. AU NCC and US IBC stand...

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A bricklayer is quoting a single-skin brick fence 22m long x 1.8m high. Before submitting the quote, they need the brick count with waste included and a quick cross-check of the m2 coverage rate they are using.

Brick & Block Calculator
Masonry
AU standard brick: ~47–50 bricks/m² (single skin, 10mm joints)
AU besser block: ~12.5 blocks/m² (390×190mm face, 10mm joints)
US modular brick: ~35 bricks/m² (~3.26 bricks/sqft)
Always order 5–10% extra for cuts and wastage. Verify bond pattern (stretcher, Flemish, stack) with your mason as this affects quantity.
ℹ️ Results are estimates for planning purposes. Verify with current standards and a qualified professional.

1 What this calculator does

Calculates the number of bricks or blocks required to build a wall from wall dimensions, brick type and joint width. Supports AU standard brick, AU Besser block, US modular brick and US standard brick. Adds 7% waste to the calculated quantity. Supports single and double-skin construction.

2 Formula & professional reasoning

Wall area = Width x Height Bricks per m2 = 1 / ((Brick length + Joint width) x (Brick height + Joint width)) AU standard brick (230x76mm) at 10mm joint: ~50 bricks/m2 AU Besser block (390x190mm) at 10mm joint: ~12.5 blocks/m2 US modular brick (194x57mm) at 10mm joint: ~55 bricks/m2 Total with waste = Wall area x Bricks/m2 x Skins x 1.07

The bricks-per-m2 rate is derived from the face area of one brick including one joint on each side. For an AU standard brick (230mm long x 76mm high) with a 10mm mortar joint: each brick unit occupies (230+10)mm x (76+10)mm = 240mm x 86mm = 0.02064 m2. So 1/0.02064 = 48.4 bricks/m2, rounded to 50 with a small adjustment for the bonding pattern. The 7% waste allowance covers cutting, chipping damage and the odd defective brick in the pack.

3 Worked examples

⚠️ Illustrative example only — not clinical or professional instruction.

Basic
Single-skin brick fence 22m x 1.8m
Given: Width: 22m | Height: 1.8m | Type: AU standard brick | Joint: 10mm | Construction: single skin
Working: Area: 22 x 1.8 = 39.6 m2 | Bricks/m2: ~50 | Base count: 39.6 x 50 = 1,980 | With 7% waste: 1,980 x 1.07 = 2,118.6 -> 2,119 bricks
Answer: 2,119 bricks (order 2,150 -- round up to pallet quantity)
💡 Bricks typically come in packs of 390-500 per pallet. Rounding to 2,200 (5-6 pallets) gives a 4% buffer which is sensible for a long masonry job.
Standard
Double-skin cavity wall 8.5m x 2.4m
Given: Width: 8.5m | Height: 2.4m | Type: AU standard | Joint: 10mm | Construction: double skin
Working: Area: 8.5 x 2.4 = 20.4 m2 | Bricks/m2: 50 | Per skin: 20.4 x 50 = 1,020 | Double skin: 1,020 x 2 = 2,040 | With 7% waste: 2,040 x 1.07 = 2,182.8
Answer: 2,183 bricks for a double-skin cavity wall
💡 A double-skin cavity wall (110mm outer skin + 50-75mm cavity + 110mm inner skin) is standard external wall construction in AU. The cavity provides insulation and weather resistance. The two skins use the same brick count.
Advanced
Besser block retaining wall with area deduction
Given: Wall: 15m x 1.2m | Minus one opening: 2.4m x 1.2m | Type: AU Besser block | Joint: 10mm
Working: Gross area: 15 x 1.2 = 18.0 m2 | Deduct opening: 2.4 x 1.2 = 2.88 m2 | Net area: 15.12 m2 | Blocks/m2: ~12.5 | Base: 15.12 x 12.5 = 189 | With 7% waste: 189 x 1.07 = 202.2
Answer: 203 Besser blocks (net area after opening deduction)
💡 Always deduct large openings (gates, doorways) from the gross wall area before calculating blocks. Small openings under 1 m2 are typically absorbed in the waste factor.

4 Sanity check

Coverage rates by brick type
AU standard (230x76mm, 10mm joint): ~50 bricks/m2 | AU Besser (390x190mm): ~12.5 blocks/m2 | US modular (194x57mm): ~55 bricks/m2 | US standard (203x65mm): ~50 bricks/m2
Joint width affects coverage significantly -- a 12mm joint on AU standard brick drops coverage to ~46 bricks/m2.
Always order in full pallet quantities
AU standard brick: 390-500 per pallet depending on supplier | Besser block: 48-72 per pallet | US modular: 500 per pallet (approx)
Ordering partial pallets incurs additional handling charges. Round up to the next full pallet.
7% waste is standard for straight brickwork
Straight walls: 7% | Complex work with many cuts (curves, arches, soldier courses): 10-15%
Mortar quantity (rough guide)
AU standard brick single skin: approximately 0.022 m3 mortar per m2 of wall | 1 bag cement + 6 bags sand per m3 of mortar

5 Common errors

ErrorCauseConsequenceFix
Not deducting large openings from the gross wall area Calculating brick count from the full wall area without removing doors, gates or windows Overordering bricks by 5-20% on walls with significant openings Deduct the area of each opening over approximately 1 m2. For openings under 0.5 m2, the waste factor typically covers any minor excess. For garage doors, gates and large window openings, always deduct the full opening area.
Using a coverage rate for the wrong joint width The calculator uses 10mm as the default joint -- some bricklayers use 8mm or 12mm Brick count off by 5-15% depending on joint width deviation The coverage rate is sensitive to joint width. For a 12mm joint on AU standard brick: (242 x 88) = 0.02130 m2 per brick unit = 46.9 bricks/m2 -- about 6% fewer bricks than at 10mm joint. Confirm the actual joint width with the bricklayer.
Not allowing for soldier courses and special details Calculating straight coursing only without identifying decorative or structural brick details Running short on special bricks or specials -- back-ordering delays the job Soldier courses (bricks on end), bull-nose corners, arch specials and sill bricks are often ordered as specials from the manufacturer. Identify these elements from the plans and order them separately from the standard brick count.
Ordering bricks without confirming the batch dye lot Bricks ordered from multiple batches Colour variation between batches -- visible as banding in the finished wall Always confirm with the supplier that sufficient bricks of the same batch are available for the entire job. Order all bricks from the same batch. For large jobs, request a written batch number confirmation on the delivery docket.