How many bricks do I need per square foot?

For standard-size bricks (8 x 2.25 inches face) with 3/8-inch mortar joints, you need approximately 6.75 bricks per square foot for a single-wythe wall. Modular bricks require about 7 per square foot due to their slightly smaller size.

What is the standard mortar joint thickness?

The standard mortar joint thickness is 10mm (3/8 inch). This applies to both bed joints (horizontal) and head joints (vertical). Some masons use 12mm (1/2 inch) joints for rustic looks, which reduces the number of bricks needed slightly.

How much waste should I plan for when ordering bricks?

Plan for 5-10% waste for simple straight walls, and 10-15% for walls with many openings, corners, or decorative patterns. The industry standard default is 7%. Waste accounts for cutting, breakage during transport, and damaged bricks.

What is the difference between single and double brick walls?

A single brick wall (4.5 inches thick) uses one wythe (layer) of bricks and is common for non-load-bearing partitions and veneers. A double brick wall (9 inches thick) uses two wythes bonded together and is used for load-bearing exterior walls. Double walls require approximately twice as many bricks.

How many bags of mortar do I need?

One standard 80 lb (36 kg) bag of pre-mixed mortar lays approximately 35 standard bricks with 10mm joints. Divide your total brick count by 35 and round up to estimate mortar bags needed. Larger bricks or thicker joints will increase mortar consumption.

Brick Calculator

Estimate how many bricks you need for any wall project. Enter wall dimensions, choose a brick size preset, set mortar thickness, subtract door and window openings, and get an accurate count with cost breakdown — all in your browser, completely free and private.

Wall Dimensions

Wall Length

Unit

Wall Height

Unit

Wall Type

Brick Size & Mortar

Brick Size Preset

Mortar Joint Thickness mm (default 10mm / 3/8 inch)

Brick Length (mm)

Brick Width (mm)

Brick Height (mm)

Openings & Waste

Number of Doors

Avg Door Size (sq ft) Standard door: ~21 sq ft (3x7)

Number of Windows

Avg Window Size (sq ft) Standard window: ~12 sq ft (3x4)

Waste Factor (%) 5-15% is typical (default 7%)

Cost Estimation (Optional)

Price per Brick ($)

Mortar Bag Price ($) ~1 bag per 35 bricks

Results

Gross Wall Area

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Net Wall Area (minus openings)

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Bricks per sq ft

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Total Bricks Needed

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Bricks (before waste)

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Mortar Bags Needed

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Brick Bond Patterns

Common laying patterns. The selected bond does not change the calculation — all patterns use roughly the same number of bricks.

Stretcher

Header

English

Flemish

How the Brick Calculator Works

This brick calculator estimates the number of bricks required for a wall based on the wall dimensions, brick size, mortar joint thickness, and any openings such as doors and windows. The formula is straightforward: calculate the net wall area (gross area minus openings), determine how many bricks fit per square foot based on the brick face area plus mortar joints, then multiply. A waste factor accounts for cuts, breakage, and transport losses — the industry standard is between 5% and 10%, depending on the complexity of the bond pattern and wall geometry.

The calculator supports both imperial (feet/inches) and metric (meters/mm) measurements. When you select a brick size preset, the tool uses the standard face dimensions (length and height) of that brick type. For custom or regional brick sizes, choose the "Custom" preset and enter exact millimeter dimensions. The mortar joint thickness (default 10mm or 3/8 inch) is added to both the brick length and height to determine the coursing module — this is how masons calculate brick counts on real job sites.

Choosing the Right Brick Size and Bond Pattern

The most common brick in North America is the Standard brick (8 x 3.625 x 2.25 inches), followed by the Modular brick which is slightly shorter in length. King Size and Queen Size bricks are larger, meaning fewer bricks per square foot and faster laying. Your choice of bond pattern — Stretcher, Header, English, or Flemish — primarily affects aesthetics and structural strength rather than total brick count. Stretcher bond is the simplest and most widely used for single-wythe walls. English and Flemish bonds alternate stretcher and header courses or bricks within a course, creating stronger and more visually interesting walls, though they require more cuts and slightly more waste.

The wall type selection matters significantly. A single brick wall (4.5 inches thick) uses one wythe of bricks. A double brick wall (9 inches thick) doubles the brick count because two wythes are laid side by side. Half brick walls use bricks on their narrow edge. Always confirm structural requirements with your local building codes, as load-bearing walls typically require double brick or reinforced construction.

Estimating Mortar and Total Project Cost

Mortar consumption is roughly one bag (typically 80 lb / 36 kg of pre-mixed mortar) per 35 standard-size bricks. This assumes standard 10mm (3/8 inch) joints. Thicker joints or irregular bricks will increase mortar usage. The cost estimation section helps you budget by multiplying the per-brick price and per-bag mortar price against the calculated quantities. Remember that labor costs — which this calculator does not include — typically account for 40-60% of the total project cost for professional bricklaying. For DIY projects, factor in tool rentals (mixing tub, trowels, level, line blocks) which typically cost between $50 and $150 per day.

To reduce waste, order about 7% more bricks than the calculated net quantity. If your wall has many corners, arches, or decorative features, increase the waste factor to 10-15%. It is always better to have a small surplus of matching bricks for future repairs than to reorder from a different batch, which may have slight color variations due to kiln temperature differences during manufacturing.