Brick & Block Calculator
Estimate the number of bricks or concrete blocks required for a wall, deduct openings, add wastage, and estimate theoretical mortar volume.
Calculate Bricks or Blocks for a Wall
Estimated Masonry Requirements
| Item | Estimate |
|---|---|
| Gross wall area | — |
| Opening area deducted | — |
| Net masonry area | — |
| Units before wastage | — |
| Wastage allowance | — |
| Units to order | — |
| Theoretical mortar volume | — |
Step-by-Step Calculation
What Is a Brick & Block Calculator?
A brick and block calculator estimates the number of masonry units required to construct a wall. It can be used for preliminary material planning, quantity take-offs and early construction estimates.
The calculation starts with the wall length and height, deducts openings such as doors and windows, estimates unit coverage from the masonry-unit dimensions and mortar joint, and then applies a wastage allowance.
How to Calculate Bricks or Blocks
Net Wall Area = Gross Wall Area − Opening Area
Unit Face Area = (Unit Length + Mortar Joint) × (Unit Height + Mortar Joint)
Base Units = Net Wall Area ÷ Unit Face Area
Units to Order = Base Units × (1 + Wastage % ÷ 100)
The calculator uses an area-based method. It is intended for estimating and does not reproduce every construction detail or bond pattern.
Brick Quantity Calculation Example
Suppose a wall is 10 m long and 3 m high, with no openings. Using a nominal 190 mm × 90 mm brick and a 10 mm mortar joint:
Unit face area = (0.190 + 0.010) × (0.090 + 0.010)
= 0.200 × 0.100 = 0.020 m²
Base units = 30 ÷ 0.020 = 1,500 bricks
With 5% wastage = 1,500 × 1.05 = 1,575 bricks
Concrete Block Calculation
Concrete blocks generally cover a larger wall area per unit than individual bricks. Select Concrete Block and enter the actual manufacturer’s length, height and width for your project.
Do not rely on a generic block size for procurement when a product-specific dimension is available.
Why Deduct Doors and Windows?
Openings do not require masonry units across their area. Enter the combined area of doors and windows to obtain a net masonry area.
For example, a door measuring 0.9 m wide by 2.1 m high has an opening area of:
How Much Wastage Should You Allow?
Wastage varies with wall geometry, cutting, breakage, handling, workmanship and site conditions. There is no single percentage suitable for every project.
The calculator uses 5% as an editable planning starting point. Adjust it to suit the project specification and procurement practice.
Estimating Mortar Volume
This is a theoretical volume estimate. Actual mortar consumption depends on joint thickness, unit tolerances, bond, workmanship and waste. Cement and sand quantities should be based on the approved mortar mix specification and project requirements.
Brickwork vs. Blockwork
- Bricks: smaller masonry units generally mean more individual pieces and more joints per unit of wall area.
- Concrete blocks: larger units can cover more wall area per piece.
- Unit dimensions: actual manufacturer dimensions should be used whenever available.
- Mortar joints: changing the joint thickness changes unit coverage and mortar requirements.
- Wastage: cutting and breakage can increase the quantity required on site.
Tips for Accurate Masonry Quantity Estimates
- Use the latest approved drawings or verified site measurements.
- Deduct significant door and window openings.
- Use actual brick or block dimensions from the supplier.
- Use the specified mortar-joint thickness.
- Apply a project-specific wastage allowance.
- Compare the calculated quantity with the BOQ and construction drawings.
- For procurement, allow for packaging and supplier-specific ordering increments where applicable.
Brick & Block Calculator FAQs
How many bricks do I need for a wall?
The quantity depends on wall area, brick dimensions, mortar joint, openings and wastage. Enter these values in the calculator to get an estimate.
How do I calculate bricks per square metre?
Estimate the face coverage of one brick including its mortar joint, then divide one square metre by that coverage. Actual consumption can vary by bond and workmanship.
Can this calculator calculate concrete blocks?
Yes. Select Concrete Block and enter the actual block length, height and width.
Does the calculator deduct doors and windows?
Yes. Enter the combined area of the openings and the calculator deducts it from the gross wall area.
What mortar joint should I use?
Use the mortar-joint thickness specified for your masonry system. The calculator defaults to 10 mm as a planning assumption.
What wastage percentage should I use?
There is no universal percentage. The calculator starts at 5% as an editable planning allowance.
Does the calculator give exact mortar quantities?
No. Mortar is estimated theoretically. Actual consumption varies with joint thickness, unit tolerances, bond, workmanship and site waste.
Can I use feet and inches?
Yes. Imperial mode uses feet for wall length and height, and inches for wall thickness, masonry-unit dimensions and mortar joints.
Does the bond pattern affect brick quantity?
Yes. Bond patterns and cutting requirements can affect actual unit consumption. This calculator uses a simplified area-based estimate.
Can I use this calculator for a BOQ?
It can support preliminary quantity take-offs, but final BOQ quantities should be checked against approved drawings, specifications and the project’s measurement rules.
Does this calculator calculate cement and sand?
It estimates theoretical mortar volume. Cement and sand quantities require an approved mortar mix specification and are therefore not automatically prescribed by this calculator.
Can I use custom brick or block sizes?
Yes. Select Custom Unit and enter the actual length, height and width of the masonry unit.
Methodology
The calculator converts the entered wall and masonry-unit dimensions into metres, calculates gross wall area, deducts opening area, estimates unit face coverage using the entered mortar joint, calculates the base unit quantity, applies the wastage percentage, and estimates theoretical mortar volume from net wall volume less masonry-unit volume.
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Disclaimer
Important: This calculator provides estimates for general construction planning. Actual masonry quantities depend on approved drawings, specifications, product dimensions, wall geometry, bond, workmanship and site conditions. Verify quantities with qualified construction professionals before procurement or execution.