Brick Calculator South Africa
Work out exactly how many bricks, blocks, bags of cement and cubic metres of sand your wall needs before you order. Pick a common project or enter your own wall dimensions, choose your brick or block type, and get an instant materials breakdown with wastage included.
Calculate My Materials ↓Brick, Block & Mortar Calculator
Select a project type or build a custom wall, choose your brick or block type, then press Calculate to see your full materials list.
Total Bricks Needed
0
Project summary
Full materials breakdown
| Material | Quantity | Unit | Notes |
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This total is based on the coverage rate for your chosen brick or block type across your wall area.
A single-skin (110mm) wall built with standard South African bricks needs roughly 50 bricks per square metre, while a double-skin (220mm) wall needs roughly 100 bricks per square metre. Concrete blocks work out to about 12.5 blocks per square metre regardless of thickness. For every 1000 bricks or blocks laid with a standard Class II mortar mix, plan for around 3 bags of cement and 0.6 cubic metres of building sand, plus 5-10% extra for wastage. Use the calculator above for an exact total based on your specific wall.
How to Use the Brick Calculator
Four quick steps to an accurate brick, block and mortar estimate for your wall.
- 1 Choose your project. Pick a common preset such as a boundary wall or garage wall, or select “Custom Wall” to enter your own length, height and any openings to deduct.
- 2 Select your brick or block type. Choose Standard/Stock brick, Maxi brick, or Concrete block depending on what you are building with.
- 3 Set your wall type and wastage. Choose single skin or double skin, and leave the wastage allowance ticked to add a standard 10% buffer for breakage and cutting.
- 4 Press Calculate. Your total bricks or blocks, cement bags and sand volume will appear instantly. Use “Copy Result” to save it for your project budget.
The Brick, Block & Mortar Formula
Brick and block quantities in South Africa are based on a fixed coverage rate per square metre for each unit type, so the calculation is a straightforward multiplication.
If Wastage Applied: Units Needed = Units Needed × 1.10
Cement (50kg bags) = Units Needed × 0.003 (3 bags per 1000 units)
Building Sand = Units Needed × 0.0006 m³ (0.6m³ per 1000 units)
Wall area is multiplied by the coverage rate for the chosen brick or block size and wall thickness to get the raw unit count, which is then rounded up to a whole unit. Cement and sand quantities follow the same per-1000-unit ratio used for a standard Class II mortar mix, then rounded up to the nearest full bag and the nearest 0.1 cubic metre of sand for practical ordering.
Worked Examples
Real project calculations using standard South African coverage rates, so you can see exactly how each total is built.
Example 1: Small boundary wall, standard brick, single skin, with wastage
| Wall area (10m x 1.8m) | 18 m² |
| Bricks needed (18 × 50, +10% wastage) | 990 bricks |
| Cement (990 × 0.003, rounded up) | 3 bags |
| Building sand (990 × 0.0006) | 0.6 m³ |
Example 2: Single garage wall, maxi brick, double skin, no wastage
| Wall area (6m x 2.4m) | 14.4 m² |
| Bricks needed (14.4 × 56, rounded up) | 807 bricks |
| Cement (807 × 0.003, rounded up) | 3 bags |
| Building sand (807 × 0.0006) | 0.5 m³ |
Example 3: Retaining/boundary wall, concrete block, single skin, with wastage
| Wall area (12m x 1.5m) | 18 m² |
| Blocks needed (18 × 12.5, +10% wastage) | 248 blocks |
| Cement (248 × 0.003, rounded up) | 1 bag |
| Building sand (248 × 0.0006) | 0.2 m³ |
Brick Calculator South Africa: The Complete Guide
Getting brick, block and mortar quantities right before you order saves you unnecessary trips to the builders merchant, avoids costly under-ordering delays, and stops you from overspending on materials you will never use. This guide explains how South African brick and block coverage rates work, what the standard sizes are, and how much mortar you actually need.
How are brick and block quantities calculated?
Unlike some rougher rules of thumb, brick and block coverage in South Africa is based on a fixed number of units per square metre of wall, determined by the unit’s face size and a standard 10mm mortar joint. Multiply your wall area by the coverage rate for your chosen brick or block type and wall thickness to get the number of units required, then add cement and sand for the mortar that binds them together.
Standard brick and block sizes in South Africa
- Standard/Stock brick: 222mm x 106mm x 73mm. The most widely used brick for house walls, both for plastered stock brick finishes and unplastered face brick walls of the same size.
- Maxi brick: 290mm x 140mm x 90mm. A larger clay or concrete brick that needs fewer units per square metre and speeds up construction, commonly used for structural and load-bearing walls.
- Concrete block: 390mm face length x 190mm face height, available in several thicknesses (commonly 90mm, 140mm and 190mm) to suit different wall depths. Popular for boundary walls, retaining walls and commercial or industrial structures.
- Paving brick: Sized and laid differently to wall bricks, since they are set flat rather than stacked in courses. Use a dedicated paving calculator rather than this wall-based tool.
Half-brick vs full-brick (single skin vs double skin) walls
A single-skin, or half-brick, wall is one brick thick and typically measures 110mm. This is the standard thickness for internal walls, garden walls and many boundary walls. A double-skin, or full-brick, wall is built as two layers of brick and measures roughly 220mm thick, and is used for external load-bearing walls that need to carry the weight of a roof or upper floor. Double-skin walls use roughly twice as many bricks per square metre as single-skin walls of the same brick type.
How much cement and sand do you need for mortar?
The Clay Brick Association of Southern Africa’s guidance for a normal, Class II strength mortar (a cement-rich mix suitable for most loadbearing and freestanding walls) works out to roughly 3 bags of 50kg cement and 0.6 cubic metres of building sand for every 1000 bricks laid, or about 1 bag of cement to every 3 wheelbarrows of sand. This calculator applies that same per-1000-unit ratio to concrete blocks as an estimate, since exact block mortar consumption depends on joint size and block type, so always confirm final quantities with your supplier for large or structural block projects. For plaster work, a rough guide is about 10 bags of cement and 2 cubic metres of sand per 100 square metres at 15mm thickness.
Mortar mix ratios explained
Most residential brickwork in South Africa uses a 1:6 cement-to-sand mortar mix by volume, which produces a Class II mortar suitable for freestanding walls, garden walls, parapets and general loadbearing brickwork. For structures exposed to severe dampness or requiring extra strength, such as certain retaining walls or below damp-proof-course work, a stronger 1:4 mix is often specified instead. Always check the mix ratio required for your specific structure, especially for retaining walls or anything load-bearing, ideally with a structural engineer or your local building inspector.
Why wastage allowance matters
Even careful bricklaying produces breakages, off-cuts around openings, and losses during delivery and handling. Adding 5-10% extra to your calculated brick or block count is standard practice in South African construction and helps avoid a second, smaller and often more expensive top-up order partway through a project.
Tips for reducing waste and overspending
- Measure openings carefully. Deduct the area of doors and windows from your total wall area rather than ignoring them, especially on smaller walls where openings make up a larger share of the surface.
- Buy from the same batch. Face bricks in particular can vary slightly in colour between production batches, so order your full quantity, plus wastage, from one batch where possible.
- Store bricks and blocks off the ground. Stacking on pallets or boards away from mud and standing water reduces breakage and staining before they are used.
- Confirm supplier stock before ordering. Popular brick and block sizes can be on backorder in some regions, so confirm availability before finalising your building schedule.
- Get a second opinion for structural or retaining walls. This calculator is for general material estimation only and does not replace an engineer’s design for retaining walls or loadbearing structures.
Methodology
Coverage rates used in this calculator reflect widely published South African construction industry figures for standard 10mm mortar joints: 50 standard bricks per square metre for a single-skin (110mm) wall, 28 maxi bricks per square metre for a single-skin wall, and 12.5 concrete blocks per square metre based on a 390mm x 190mm block face. Double-skin figures are calculated as double the single-skin rate. Cement and sand quantities are based on the Clay Brick Association of Southern Africa’s published guidance of roughly 3 bags of cement and 0.6 cubic metres of sand per 1000 bricks for a Class II mortar mix. Actual requirements can vary based on brick and block batch size, mortar joint thickness, wall bonding pattern, and site conditions, so always confirm exact quantities with your supplier or builder before ordering for a project where accuracy is critical.
Assumptions used in this calculator
- All coverage rates assume a standard 10mm mortar joint.
- Wastage, when applied, adds an estimated 10% to the raw brick or block count.
- Cement and sand figures use the same per-1000-unit ratio for bricks and concrete blocks as a general estimate.
- Preset projects use approximate typical dimensions and may not reflect your exact wall size or bonding pattern.
- This tool does not calculate reinforcing steel, foundations, plaster, or paint quantities.
Frequently Asked Questions
For a standard South African brick (222 x 106 x 73mm) with a 10mm mortar joint, you need approximately 50 bricks per square metre for a single-skin (110mm) wall, and roughly 100 bricks per square metre for a double-skin (220mm) wall. Maxi bricks need fewer units, at around 28 per square metre single skin. Use the calculator above for an exact figure based on your wall size.
The standard, or stock, brick used in South Africa measures 222mm x 106mm x 73mm. This is the most common brick size for both plastered stock brick walls and unplastered face brick finishes. Maxi bricks are larger at 290mm x 140mm x 90mm, and are chosen for faster, stronger construction with fewer units per square metre.
A standard South African concrete block, with a 390mm x 190mm face, works out to roughly 12.5 blocks per square metre of wall, regardless of the block’s thickness (commonly 90mm, 140mm or 190mm). This makes blockwork significantly faster to build than brickwork, since far fewer units are needed to cover the same area.
A half-brick wall, also called single skin, is one brick thick, typically around 110mm, and is commonly used for internal walls and garden or boundary walls. A full-brick wall, or double skin, is built with two layers of brick for a thickness of around 220mm, and is used for external loadbearing walls that need to support a roof or upper floor.
For a standard Class II mortar mix, the Clay Brick Association of Southern Africa’s guidance works out to roughly 3 bags of 50kg cement and 0.6 cubic metres of building sand per 1000 bricks, or about 1 bag of cement to every 3 wheelbarrows of sand. Stronger mixes for loadbearing or exposed structures use more cement relative to sand.
A wastage allowance of 5-10% is standard practice in South African construction to cover breakage, cutting around openings, and losses during delivery and handling. This calculator applies an estimated 10% when the wastage option is selected.
Yes. Alongside the standard/stock brick, you can select maxi brick or concrete block from the material dropdown, and the calculator will apply the correct coverage rate and mortar estimate for each unit type and wall thickness.
This calculator provides a general materials estimate only. For retaining walls, loadbearing structures, or anything requiring council approval, it’s best to consult a structural engineer or your local municipality’s building control department before starting construction.