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Brick Calculator

Calculate how many bricks you need for a wall, including mortar joints, doors, windows and waste — metric or imperial, with regional brick-size presets.

This brick wall calculator estimates material quantity from the wall size, brick size and joint you enter. It does not check structural wall design, footings, reinforcement or building-code compliance — see Limitations below.
Wall & Brick Details

Wall sections

LengthHeightQty

Openings (doors, windows) — optional

WidthHeightQty

mm
mm

mm


Cost (optional)

Results
Bricks Required
ItemValue

Written and reviewed by Mohsin Iqbal · Last reviewed August 2026

Brick Calculator

This calculator for bricks estimates how many bricks you need for a wall from your wall dimensions, brick size, mortar-joint thickness, openings and waste allowance. It works as a brick wall calculator for single or multiple wall sections, subtracts doors and windows, and gives you bricks per square foot or square metre alongside the final whole-brick quantity to buy.

How to Use the Brick Calculator

  1. Choose your unit — millimetres, centimetres, metres, inches or feet.
  2. Add your wall section(s) — length, height and a quantity if you have several identical walls. Use "+ Add another wall" for different-sized sections (rooms, extensions, multiple elevations).
  3. Add any openings — doors, windows or other openings with width, height and quantity.
  4. Choose a brick size — a regional preset or your own custom brick dimensions — and set your mortar-joint thickness.
  5. Add a waste allowance and, optionally, a price per brick for an estimated material cost.

How Many Bricks Do I Need?

Divide your net wall area (wall area minus door and window area) by the effective brick module — the brick's face area plus its mortar joint — then round up and add a waste allowance. There's no single number that fits every project: brick size and joint thickness both change the answer, sometimes significantly. Enter your own dimensions above for an exact figure.

Brick Wall Calculator Formula

Gross Wall Area = Wall Length × Wall Height
Net Wall Area = Gross Wall Area − Opening Area
Effective Brick Module = (Brick Length + Joint) × (Brick Height + Joint)
Bricks Before Waste = Net Wall Area ÷ Effective Brick Module
Final Bricks = ROUND UP[ Bricks Before Waste × (1 + Waste %) ]

The calculator keeps every measurement internally consistent in one base unit before applying this formula, then converts the results back to your display unit — so switching between metric and imperial never changes the underlying quantity, only how it's displayed.

How Many Bricks per Square Foot?

It depends entirely on the brick size and mortar joint you use, so there's no single correct number. For a common US modular brick (7-5/8 × 2-1/4in) with a 3/8in joint, the effective module is 8in × 2-5/8in = 21 sq in, which works out to about 6.9 bricks per square foot. A larger brick or a thicker joint needs fewer bricks per square foot; a smaller brick or thinner joint needs more. Use the calculator above with your own brick size for an exact figure.

How Many Bricks per Square Metre?

Again, this depends on brick size and joint thickness. For a UK standard brick (215 × 65mm) with a 10mm joint, the effective module is 225mm × 75mm = 0.016875 m², which works out to about 59.3 bricks per square metre. A larger Australian standard brick (230 × 76mm) with the same 10mm joint needs closer to 48.5 bricks per square metre, since each brick covers more wall face. Always state your brick size and joint when comparing bricks-per-area figures.

Standard Brick Sizes

RegionExample brickActual dimensions (L × H × W)Typical joint
United KingdomUK Standard (Work Size)215 × 65 × 102.5mm10mm
United StatesUS Modular7-5/8 × 2-1/4 × 3-5/8in3/8in (~9.5mm)
AustraliaAustralian Standard230 × 76 × 110mm10mm
CanadaMetric Modular (common)190 × 57 × 90mm10mm
New ZealandCommon NZ brick230 × 76 × 110mm (commonly aligned with AU standard)10mm

These are commonly cited reference dimensions, not a single global standard — brick sizes vary by manufacturer, product line and country, and several other sizes (US Queen, King and Utility bricks; UK metric and imperial variants) are also widely sold. Always check the actual brick dimensions supplied by your manufacturer before ordering materials, and use the Custom brick size option above to enter them exactly.

How Mortar Joints Affect Brick Quantity

The mortar joint matters more than people expect. A brick doesn't occupy just its own bare face on the wall — it occupies its face plus half the mortar joint on each side, which is why this calculator adds the joint thickness to both the brick's length and height before working out how many bricks fit a given wall area. Leaving the joint out of the calculation makes the bare brick face look smaller than it actually occupies on the wall, which overstates the number of bricks needed — dividing the wall area by a smaller-than-real brick module returns more bricks than the wall will actually take.

How to Subtract Doors and Windows

Add each door, window or other opening's width, height and quantity in the Openings section above. The calculator multiplies each opening's width by height by quantity, adds all openings together, and subtracts that total from the gross wall area to get the net brickwork area used in the brick-count formula. If your total opening area is greater than or equal to your total wall area, the calculator shows an error instead of returning a negative or nonsensical brick count.

Brick Waste Allowance

Waste allowance covers bricks lost to cutting, breakage, damaged units, corners, and pattern or bond complexity. There's no universally correct figure — 5% is a common starting point for a simple straight wall, while more complex bond patterns, feature walls or projects with many corners and cuts often justify 10% or more. Choose an allowance that reflects your specific project, or set it to 0% if you're calculating a bare minimum quantity.

Brick Cost Estimate

Used as a brick estimator, this section turns your final brick quantity into a rough material cost: enter a price per brick and currency above, and it multiplies final brick quantity × price per brick. This calculator doesn't publish or assume brick prices, since they vary enormously by region, brick type and supplier — you enter your own local price. The estimate covers brick material only; it doesn't include labour, mortar, delivery, scaffolding, wastage beyond your selected allowance, or tax unless you factor those in separately.

Worked Examples

Example 1 — Metric wall

StepWorkingResult
Wall5m × 2.4m, UK Standard brick (215 × 65mm), 10mm joint, 5% waste12 m² gross
Effective module(215+10) × (65+10) = 225 × 75mm0.016875 m²
Bricks before waste12 ÷ 0.016875711.11 → 712 bricks
+5% waste711.11 × 1.05 = 746.67, round up747 bricks

Example 2 — Imperial wall

StepWorkingResult
Wall20ft × 8ft, US Modular brick (7-5/8 × 2-1/4in), 3/8in joint, 10% waste160 ft² gross
Effective module(7.625+0.375) × (2.25+0.375) = 8 × 2.625in21 sq in (0.1458 ft²)
Bricks before waste160 ÷ 0.14581,097.14 → 1,098 bricks
+10% waste1,097.14 × 1.10 = 1,206.86, round up1,207 bricks

Example 3 — Wall with a door

StepWorkingResult
Wall6m × 2.7m, Australian Standard brick (230 × 76mm), 10mm joint, 5% waste16.2 m² gross
Door opening0.9m × 2.1m1.89 m²
Net area16.2 − 1.8914.31 m²
Effective module(230+10) × (76+10) = 240 × 86mm0.02064 m²
Bricks before waste14.31 ÷ 0.02064693.31 → 694 bricks
+5% waste693.31 × 1.05 = 727.98, round up728 bricks

Common Brick Calculation Mistakes

  1. Ignoring the mortar joint. Using the bare brick face instead of brick-plus-joint overstates the brick count, sometimes significantly, since it divides the wall area by a smaller-than-real module.
  2. Forgetting to subtract openings. Doors and windows can easily account for 10-20% of a wall's gross area on a typical house elevation.
  3. Using someone else's "standard brick" size. Brick dimensions vary by country and manufacturer — always confirm your actual brick size rather than assuming a generic figure.
  4. Applying no waste allowance on a project with corners, cuts or a complex bond pattern, then running short on-site.
  5. Mixing units — entering wall dimensions in one system and brick dimensions in another without converting first.

Does Brick Bond Affect the Number of Bricks?

The wall-area-divided-by-brick-module formula used here is a reasonable estimate for most common bond patterns, including running (stretcher) bond, English bond and Flemish bond, since it's based on the visible brick face area rather than a specific laying pattern. However, bond pattern genuinely affects real-world cutting, header placement, waste and appearance — a Flemish or English bond with headers and half-bats typically involves more cutting than a simple running bond. This calculator doesn't model bond-specific cutting patterns in detail; increase your waste allowance for more complex bonds.

Limitations and Assumptions

This calculator estimates brick quantity, area and material cost from the wall dimensions, brick size, joint thickness, openings and waste allowance you enter. It does not check structural wall design, footing requirements, reinforcement, wall thickness or leaf/wythe arrangement, or building-code compliance. The formula is based on the visible wall-face area, so it applies the same whether the wall is a single veneer leaf, one wythe of a cavity wall, or a solid wall — it doesn't calculate additional leaves, ties or backing structure. Bond pattern, cutting layout and workmanship are not modelled in detail; use the waste allowance to account for these. Always confirm brick dimensions with your manufacturer and structural requirements with a qualified professional before ordering materials or beginning construction.

Frequently Asked Questions