Brick Calculator
Calculate bricks and mortar for a wall using US modular, UK/EU or Australian brick sizes, single or double skin, with openings and waste.
✓ Method shownUpdated By DIYCalcLab Editorial TeamSources (3)How we calculate
Quick answer: A 20 × 4 ft single-skin wall of US modular brick with 3/8 in joints needs 576 bricks (6.86 per sq ft, +5%) and about 8 bags of 80 lb mortar mix. A 6 × 1.2 m wall of UK 215 × 65 mm bricks with 10 mm joints needs 448 bricks (59.3 per m², +5%). Bricks per area = 1 ÷ ((brick length + joint) × (brick height + joint)).
Result
Bricks (incl. 5% waste)
576 bricks
- Bricks per sq ft
- 6.86
- Wall area
- 80 sq ft
- Mortar (incl. 10%)
- 4.9 cu ft
- Mortar bags
- 8
- Free-standing single-skin walls taller than about 4 ft (1.2 m) need piers or engineering — check local guidance.
Show the math
- Wall area = L × H − openings = 80 sq ft
- Bricks per sq ft = 1 ÷ ((brick L + joint) × (brick H + joint)) = 6.86
- × area × 1 skin(s) × (1 + 5%) → 576
- Mortar = wall volume − brick volume (+10%) = 4.87 cu ft → 8 bags
Shopping list & cost
| Item | Spec | Qty | Cost |
|---|---|---|---|
| Bricks | US modular 7⅝ × 2¼ × 3⅝ in | 576 | — |
| Mortar | 80 lb mortar mix | 8 bags | — |
Prices are what you enter under Advanced options. Estimates only — check stock and pricing with your supplier.
Diagram
How to use this calculator
- Measure the wall length and height; subtract windows and doors under Advanced.
- Pick your brick size — US modular, US queen, UK/EU standard or Australian.
- Choose single skin (half-brick, ~4 in / 100 mm) or double skin (one brick thick).
- Leave joint blank to use the standard joint for that brick.
- Use the mortar bag count as a guide; site-mixed mortar is cheaper for big walls.
Method & assumptions
Bricks per area = 1 ÷ ((Brick L + Joint) × (Brick H + Joint)) Bricks = Wall area × Bricks per area × Skins × (1 + waste %) Mortar = Wall area × Brick depth − Bricks × Brick volume (+10%)
- Joint
- ⅜ in (US) or 10 mm (UK/EU/AU)
- Skin
- one leaf of brickwork
Assumptions & limits
- Stretcher bond; decorative bonds with headers need more bricks.
- Mortar figure excludes the collar joint in solid walls beyond one joint width.
- Not a structural design: retaining walls, tall free-standing walls and load-bearing walls need engineering and local approval.
Rounding: purchase quantities are always rounded up to whole bags, boxes, sheets or bundles. See our methodology.
Worked examples
Imperial: garden wall 30 × 3 ft, US modular, single skin
- Area = 90 sq ft × 6.857 = 617.1 bricks
- +5% = 648 bricks
Metric: 10 × 1 m wall, UK bricks, double skin
- 10 m² × 59.26 × 2 = 1,185 bricks; +5% = 1,245
- Mortar ≈ 0.5 m³ including the collar joint and 10% — buy sand and cement in bulk
In depth: bricks planning notes
Brick sizes and joints by country
Brick sizes are standardised differently around the world. In the US, a modular brick is 7⅝ × 2¼ × 3⅝ in and, with ⅜ in joints, gives a nominal 8 × 2⅔ in face. Queen and engineer sizes differ slightly. UK and European bricks are 215 × 102.5 × 65 mm with 10 mm joints, which gives 60 bricks per square metre in a single skin — a figure bricklayers use every day. Australian bricks are typically 230 × 110 × 76 mm, giving about 48 per square metre.
Joint thickness has a big effect. A UK wall laid with 12 mm joints needs about 3% fewer bricks than one with 10 mm joints but more mortar. The calculator lets you choose the brick standard and the joint so the count matches what you will actually build.
Walls, piers and mortar
A single-skin (half-brick) wall is one brick thick and suitable only for low garden walls and planters. A one-brick (double-skin) wall uses two skins tied together, either with headers in the bond or with wall ties, and is much stronger. Taller freestanding walls need piers at intervals and an adequate foundation; above about 1 m (3–4 ft) or for any retaining wall, follow local guidance or ask an engineer.
Mortar is estimated as the wall volume minus the bricks, plus waste. Frogged bricks laid frog-up, wide joints and rough work all use more. Bagged ready-mixed mortar suits small jobs; for larger walls, a typical general-purpose mix is about 1 part cement to 5 or 6 parts building sand with plasticiser — follow the mix recommended for your bricks and exposure.
Order a few percent extra bricks for cutting and breakage, and take bricks from several packs as you lay to blend colour. Protect fresh brickwork from frost and heavy rain.
Reference table
| Brick | Per area |
|---|---|
| US modular 7⅝ × 2¼ in, ⅜ in joint | 6.86 per sq ft |
| US queen 7⅝ × 2¾ in | ≈ 5.76 per sq ft |
| UK/EU 215 × 65 mm, 10 mm joint | 59.3 per m² (60 is the usual figure) |
| AU 230 × 76 mm, 10 mm joint | ≈ 48.4 per m² |
Key facts
- UK rule of thumb
- 60 bricks per m² (single skin)
- US rule of thumb
- 7 bricks per sq ft
- Waste allowance
- 5% (10% with many cuts)
Tips & common mistakes
- Order all bricks at once and mix from several packs to avoid colour banding.
- Don't lay bricks in frost or heavy rain; protect fresh work.
- Free-standing walls need movement joints and piers at intervals — check local guidance.
Frequently asked questions
How many bricks per square metre?
About 60 UK/EU standard bricks (215 × 65 mm) with 10 mm joints for a single-skin wall — 120 for double skin.
How many bricks per square foot?
About 6.9 US modular bricks with ⅜ in joints — 7 is the usual rule of thumb.
How much mortar do I need for 1,000 bricks?
For solid UK bricks with 10 mm joints our formula gives about 0.3 m³ (10.5 cu ft) per 1,000 bricks before waste. Frogged bricks laid frog-up and thicker joints use much more, so many merchants plan on 0.5–0.6 m³.
What is the difference between single and double skin?
A single skin is one brick wide (half-brick thickness). A double skin (one-brick wall) is two leaves bonded or tied together.
How tall can a single-skin garden wall be?
Guidance varies by region and wind exposure; many sources limit unreinforced half-brick walls to about 1 m without piers. Check local rules.
Sources
- Brick Industry Association – Technical Notes — checked 2026-10; verify before launch
- Brick Development Association (UK) — checked 2026-10; verify before launch
- Think Brick Australia — checked 2026-10; verify before launch
Default values (bag yields, coverage rates, densities) are typical figures from manufacturer literature. Always check the label on the product you buy.
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Cite or embed this calculator
DIYCalcLab. “Brick Calculator.” Oct 18, 2026. https://diycalclab.com/masonry/brick-calculator/
An embeddable version for blogs and contractor sites is planned.
Estimates only. Verify quantities with your supplier and local building codes. For structural, electrical or safety-critical work, consult a licensed professional. Full disclaimer.