Maxi Brick Calculator
Work out exactly how many maxi bricks, bags of cement and cubic metres of building sand your wall needs before you order. Maxi bricks (290 x 140 x 90mm) cover more wall area per unit than a standard brick, so fewer are needed and building is faster. This tool applies South African coverage rates and Clay Brick Association mortar guidance to give you a complete materials breakdown in seconds. Pick a common project or enter your own wall dimensions to get an instant, wastage-included estimate.
Calculate My Maxi Bricks ↓Maxi Brick Calculator
Select a project type or enter your own wall dimensions, choose single or double skin, then press Calculate to see your full maxi brick and mortar materials list.
Total Maxi Bricks Needed
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Project summary
Full materials breakdown
| Material | Quantity | Unit | Notes |
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This total is based on the standard maxi brick coverage rate for your chosen wall area and thickness.
A South African maxi brick (290 x 140 x 90mm) requires approximately 28 maxi bricks per square metre for a single-skin (140mm) wall with a 10mm mortar joint, and approximately 56 maxi bricks per square metre for a double-skin (290mm) wall. Compare this to 50 standard bricks per square metre single skin, so maxi bricks use roughly 44% fewer units for the same wall face area. For mortar, plan for approximately 3 bags of 50kg cement and 0.6 m³ of building sand per 1000 maxi bricks at a standard 1:6 Class II mix. Always add 10% wastage for breakage, cutting and handling losses.
How to Use the Maxi Brick Calculator
Four quick steps to an accurate maxi brick and mortar estimate for your wall.
- 1 Choose your project. Pick a common preset such as a maxi brick boundary wall or room addition, or select “Custom Wall” to enter your own length, height and any openings to deduct.
- 2 Select maxi brick type. Choose clay or concrete maxi brick. Both use the same standard 290 x 140 x 90mm dimensions and the same coverage rate, so your total quantity will be the same either way.
- 3 Set your wall thickness and wastage. Choose single skin for boundary and garden walls, or double skin for loadbearing external walls. Leave the wastage allowance ticked to add a standard 10% buffer.
- 4 Press Calculate. Your total maxi bricks, cement bags and sand volume appear instantly. Use “Copy Result” to save the breakdown for your materials order or project budget.
The Maxi Brick Formula
Maxi brick quantities are calculated from a fixed coverage rate per square metre based on the brick’s face size and a standard 10mm mortar joint.
If Wastage Applied: Maxi Bricks Needed = Maxi Bricks Needed × 1.10
Cement (50kg bags) = Maxi Bricks Needed × 0.003 (approx. 3 bags per 1000 bricks)
Building Sand (m³) = Maxi Bricks Needed × 0.0006 (approx. 0.6 m³ per 1000 bricks)
The coverage rate of 28 maxi bricks per square metre for a single-skin wall is derived from the brick’s face dimensions (290mm length × 90mm height) plus a standard 10mm mortar joint on each edge: (290 + 10) × (90 + 10) = 300mm × 100mm = 0.03 m² per brick, giving 1 ÷ 0.03 = 33.3, rounded to 28 in industry practice to allow for mortar joint volume and minor variation. Cement and sand quantities are based on Clay Brick Association of Southern Africa guidance for a standard Class II 1:6 mortar mix. Quantities are rounded up to the nearest whole bag and nearest 0.1 m³ of sand for practical ordering.
Worked Examples
Real project calculations using standard South African maxi brick coverage rates.
Example 1: Maxi brick boundary wall, single skin, with wastage
| Wall area (10m x 1.8m) | 18 m² |
| Maxi bricks (18 × 28, +10% wastage) | 554 bricks |
| Cement (554 × 0.003, rounded up) | 2 bags |
| Building sand (554 × 0.0006, rounded up) | 0.4 m³ |
Example 2: Maxi brick garage wall, double skin, with wastage
| Wall area (6m x 2.4m) | 14.4 m² |
| Maxi bricks (14.4 × 56, +10% wastage) | 887 bricks |
| Cement (887 × 0.003, rounded up) | 3 bags |
| Building sand (887 × 0.0006, rounded up) | 0.6 m³ |
Example 3: Maxi brick room addition, 4 walls approx. 40 m², single skin, with wastage
| Wall area (approx. 4 walls) | 40 m² |
| Maxi bricks (40 × 28, +10% wastage) | 1,232 bricks |
| Cement (1,232 × 0.003, rounded up) | 4 bags |
| Building sand (1,232 × 0.0006, rounded up) | 0.8 m³ |
Maxi Brick Calculator: The Complete Guide
Maxi bricks are one of the most popular choices for residential and commercial walling in South Africa, particularly for boundary walls, room additions and affordable housing projects. Their larger size means fewer units are needed per square metre, walls go up faster, and less mortar is consumed per square metre of wall face compared to standard bricks. Getting your maxi brick and mortar quantities right before you order prevents costly under-ordering or over-ordering and keeps your project on budget.
What is a maxi brick and what are its dimensions?
A maxi brick is a larger clay or concrete brick manufactured to a nominal size of 290mm x 140mm x 90mm in South Africa. The actual work size, accounting for a standard 10mm mortar joint, gives a unit that covers a face area of 300mm x 100mm when laid, or 0.03 m² per brick. This is significantly larger than the standard South African stock brick (222 x 106 x 73mm), which covers only about 0.02 m² per brick at the same joint size. The result is that a maxi brick wall requires roughly 44% fewer units per square metre compared to a standard brick wall of the same thickness and height.
How many maxi bricks per square metre?
The standard South African coverage rate for maxi bricks is approximately 28 bricks per square metre for a single-skin (140mm) wall and 56 bricks per square metre for a double-skin (290mm) wall, both with a standard 10mm mortar joint. These are the figures published and widely used across the South African construction industry and are consistent with the Clay Brick Association of Southern Africa’s coverage guidance. Compare this to 50 standard bricks per square metre for a single-skin wall, confirming the significant material saving maxi bricks offer per square metre of wall.
Clay maxi brick vs concrete maxi brick
Both clay and concrete maxi bricks are manufactured to the same nominal 290 x 140 x 90mm dimensions in South Africa, so the coverage rate and brick quantity calculation is identical for both types. The choice between them depends on other factors:
- Clay maxi bricks are fired in a kiln and typically offer better thermal performance, greater durability in freeze-thaw conditions, and a more consistent appearance for face-brick finishes. They are generally considered the higher-quality option for plastered and unplastered walls alike.
- Concrete maxi bricks are cast from a cement and aggregate mix, are widely available across South Africa and are often more affordable than clay maxi bricks. They are commonly used for plastered walls, boundary walls and affordable housing where visual appearance of the raw brick is less important.
Single-skin vs double-skin maxi brick walls
A single-skin maxi brick wall is one brick wide, measuring 140mm thick (the width of a maxi brick). This is the most common construction for boundary walls, garden walls and room-addition walls in South Africa. A double-skin maxi brick wall is two bricks wide, measuring 290mm thick (the length of a maxi brick), and is used for external loadbearing walls that need to carry the weight of a roof, upper floor or significant wind load. Double-skin walls require approximately twice as many bricks and twice as much mortar per square metre of wall face as single-skin walls.
How much mortar do maxi bricks need?
For a standard Class II 1:6 mortar mix (one part cement to six parts building sand by volume), the Clay Brick Association of Southern Africa’s guidance works out to approximately 3 bags of 50kg cement and 0.6 cubic metres of building sand per 1000 bricks laid with a 10mm joint. This calculator applies that same ratio to maxi bricks as a practical estimate. Because maxi bricks are larger, each brick displaces more mortar per unit than a standard brick, but the total mortar volume per square metre of wall is broadly similar since fewer units are laid. For large projects, always confirm final mortar quantities with your supplier.
Maxi brick vs standard brick: which should you use?
The main advantages of maxi bricks over standard bricks for South African residential projects are speed and economy of labour. Fewer bricks to lay per square metre means a faster build and lower labour cost per square metre of wall. Maxi bricks are particularly well suited to:
- Boundary walls and perimeter fencing
- Garden and retaining walls
- Room additions and outbuildings
- Affordable housing and low-cost construction
- Any project where plastering will cover the finished brickwork
Standard bricks remain preferred for unplastered face-brick finishes on main house walls where a traditional appearance is required, and in some areas where maxi brick availability or local building practice favours the smaller unit. For structural or loadbearing applications, always confirm the appropriate brick specification with a structural engineer.
Mortar mix ratios for maxi brick walls
Most maxi brick walls in South Africa are built with a standard 1:6 cement to building sand mortar mix (Class II), which produces adequate strength for boundary walls, garden walls and single-storey room additions. A stronger 1:4 mix is recommended for walls exposed to severe weather, below damp-proof-course work, retaining walls subject to soil pressure, or any loadbearing application specified by an engineer. This calculator uses the 1:6 mortar ratio as the default for the cement and sand quantities shown.
Why wastage allowance matters for maxi bricks
Even with careful ordering and bricklaying, maxi bricks are lost to breakage during delivery and handling, cutting around door and window openings, and off-cuts at corners and reveals. Adding 10% to your calculated quantity is standard practice in South Africa. Because maxi bricks are larger than standard bricks, each broken unit represents a larger material loss, making the wastage allowance particularly important for smaller projects where a single broken pallet of bricks can significantly affect your total.
Tips for maxi brick projects
- Deduct openings accurately. Doors and windows reduce the number of maxi bricks needed. Deduct their combined area from your total wall area before calculating, especially on smaller walls where openings represent a larger proportion of the surface.
- Order from the same batch. Clay maxi bricks can vary slightly in colour between production batches. Order your full quantity including wastage from one batch to avoid colour variation if the wall will be left unplastered.
- Store on pallets off the ground. Keep maxi bricks off bare earth and covered until needed to avoid mud contamination, staining and chipping before installation.
- Check foundation design for double-skin walls. A double-skin maxi brick wall is significantly heavier than a single-skin wall. Confirm that your footing design is adequate for the increased load with a structural engineer or your building inspector.
- Confirm local building requirements. Boundary walls above a certain height typically require building plan approval from your local municipality in South Africa. Check the required height limits and setback rules in your area before construction.
Methodology
Coverage rates used in this calculator reflect standard South African construction industry figures for maxi bricks with a 10mm mortar joint: 28 maxi bricks per square metre for a single-skin (140mm) wall and 56 maxi bricks per square metre for a double-skin (290mm) wall. Cement and sand quantities are based on Clay Brick Association of Southern Africa guidance of approximately 3 bags of 50kg cement and 0.6 m³ of building sand per 1000 bricks for a Class II 1:6 mortar mix. A 10% wastage factor is applied when selected. Cement bags are rounded up to the nearest whole bag and sand is rounded up to the nearest 0.1 m³ for practical ordering. Actual quantities may vary based on mortar joint thickness, bonding pattern, brick batch variation and site conditions.
Assumptions used in this calculator
- All coverage rates assume a standard 10mm mortar joint.
- Single-skin wall: 28 maxi bricks per m². Double-skin wall: 56 maxi bricks per m².
- Cement and sand quantities use Clay Brick Association guidance of 3 bags cement and 0.6 m³ sand per 1000 bricks at a 1:6 Class II mix.
- Wastage, when applied, adds 10% to the raw brick count and all mortar quantities.
- Clay and concrete maxi bricks use the same coverage rate as both are manufactured to the same nominal 290 x 140 x 90mm dimensions.
- Preset projects use typical dimensions. Enter Custom Wall for your exact measurements.
- This tool does not calculate reinforcing steel, foundations, plaster, DPC or material costs.
Frequently Asked Questions
A South African maxi brick (290 x 140 x 90mm) requires approximately 28 bricks per square metre for a single-skin (140mm) wall and 56 bricks per square metre for a double-skin (290mm) wall, both with a standard 10mm mortar joint. Compare this to 50 standard bricks per square metre single skin, which shows that maxi bricks use roughly 44% fewer units for the same wall face area.
The standard South African maxi brick is manufactured to a nominal size of 290mm long x 140mm wide x 90mm high. This applies to both clay and concrete maxi bricks. With a standard 10mm mortar joint added to each face, the work size is 300mm x 100mm, giving a face area of 0.03 m² per brick and a coverage rate of approximately 28 bricks per square metre for a single-skin wall.
Both are manufactured to the same 290 x 140 x 90mm dimensions so the quantity needed per square metre is identical. Clay maxi bricks are kiln-fired and generally offer better thermal performance and durability for face-brick finishes. Concrete maxi bricks are cast from a cement mix, are widely available and are typically more affordable. For plastered walls, either type performs well. For unplastered face-brick finishes, clay is generally preferred for consistent appearance.
For a standard 1:6 Class II mortar mix, approximately 3 bags of 50kg cement and 0.6 m³ of building sand are needed per 1000 maxi bricks, based on Clay Brick Association of Southern Africa guidance. For a stronger 1:4 mix used on exposed or loadbearing walls, plan for approximately 4–5 bags of cement and 0.5–0.6 m³ of sand per 1000 bricks. Always add 10% wastage for mixing losses.
A single-skin maxi brick wall is one brick wide, measuring 140mm thick (the nominal width of a maxi brick). A double-skin maxi brick wall is two bricks wide, measuring 290mm thick (the nominal length of a maxi brick). For comparison, a single-skin standard brick wall is 110mm thick and a double-skin standard brick wall is 220mm thick.
Maxi bricks typically cost more per unit than standard bricks, but because you need roughly 44% fewer of them per square metre of wall, the total material cost can be similar or lower overall. The biggest saving with maxi bricks is often in labour: fewer bricks to lay per square metre means faster construction and lower bricklaying costs per square metre of finished wall.
Select “Custom Wall” from the project dropdown, enter your wall length and height in metres, then enter the combined area of all doors and windows in the deduction field. The calculator subtracts the opening area from your total wall area before calculating the brick and mortar quantities, giving you an accurate estimate that avoids over-ordering for space that will not be bricked up.