Brick & Block Calculator
Work out how many bricks or blocks and how many bags of mortar your wall needs, accounting for openings and waste.
m
m
m²
Unit type
%
- 1
Net wall area
5 × 2.4 − 1.8 = 10.2 m² - 2
Waste factor
1 + 10 ÷ 100 = 1.1 - 3
Raw unit count
10.2 × 60 × 1.1 = 673.2 - 4
Bricks needed (rounded up)
ceil(673.2) = 674Rounded up to the nearest whole unit — never order less than this.
How does this calculator work?
Multiply wall length by height, subtract openings to get net area, then multiply by about 60 bricks (or 10 blocks) per square metre and add roughly 10% for waste. Mortar runs near 0.02 m³ per square metre for brick, divided by bag yield to get bags. Round everything up.
Formula
How this is calculated
First the calculator finds the net wall area by multiplying wall length by wall height and subtracting the total area of any doors and windows (openings). Length and height are in metres, openings in square metres, so the net area comes out in square metres.
The unit count depends on the brick or block type. A single-skin wall of standard bricks with 10 mm mortar joints uses about 60 bricks per square metre, while standard concrete blocks use about 10 per square metre. The net area is multiplied by this rate and by a waste factor (1 + waste%, default 10%) to cover cuts and breakage, then rounded up to a whole unit.
Mortar is estimated from a typical volume per square metre (about 0.022 m³/m² for brick, 0.009 m³/m² for block) and divided by the usable yield of a 25 kg bag (about 0.017 m³) to give whole bags. These are estimates: actual quantities vary with joint thickness, wall thickness (single vs double skin), brick dimensions, and mix ratio, so always allow a margin.
Frequently asked questions
For a single-skin wall of standard bricks with 10 mm mortar joints, roughly 60 bricks per square metre. Concrete blocks are larger, so about 10 per square metre.
Bricks break and many need to be cut at corners, ends and around openings. A 10% allowance is typical, but increase it for complex walls or inexperienced bricklayers.
The brick rate assumes a single skin. For a double-skin or cavity wall with two leaves, roughly double the brick count and mortar.
Also known as
TG we-Calculate Editorial Team. (2026). Brick & Block Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/brick-calculator
TG we-Calculate Editorial Team. "Brick & Block Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/brick-calculator.
TG we-Calculate Editorial Team, "Brick & Block Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/brick-calculator
@misc{wecalculate_brick_calculator, title = {Brick & Block Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/brick-calculator}}, year = {2026}, note = {TG we-Calculate} }
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