TAHA Engineering Toolsby TAHA Knowledge Lab

Civil & Construction

Bricks & Blocks Calculator

Number of bricks or blocks for a wall, with door and window openings deducted.

Inputs

Brick wall elevation with length L, height H and a window opening, and a single brick showing unit length l, unit height h and joint thickness j.openingL — wall lengthHlhjjoint
Left: wall of length L and height H with an opening deducted. Right: one unit with length l and height h; each unit is counted with one mortar joint j on its length and one on its height. Diagram not to scale.

Actual size of your brick or block from the manufacturer. The values shown are only an example.

Enter 0 for thin-joint or dry-stacked blocks.

For a two-unit-wide wall the count is doubled. Header bonds use the same total number of units in practice, but check your bond pattern.

For breakage and cutting. Use your own site figure.

Result

Units to buy (with wastage, rounded up)
516units
Units needed (before wastage)
491.176units
Units per m² of wall face
49.0196per m² (per leaf)
Wall area
15
Openings area
4.98
Net wall area
10.02
Wall thickness (nominal)
110

The net wall area is 10.02 m². At 49.0196 per m² (per leaf), you need about 491.176 units; with 5% wastage, buy about 516 units.

  • Count = net wall area ÷ (unit length + joint) × (unit height + joint) × units across the wall thickness. Each unit is counted with one joint on its length and one on its height, so joints are not counted twice.

Educational estimate — check the assumptions below.

About this calculator

This calculator estimates how many bricks or blocks you need for a wall. Enter the wall size, deduct doors and windows, and enter the real dimensions of your brick or block and the mortar joint. Brick sizes differ between countries and manufacturers, so the example values are only a starting point — always use the dimensions of the units you will buy.

Formula

Net area = L × H − Σ (opening width × height × number)

Units per m² = 1 ÷ [(l + j) × (h + j)]

Units = Net area × Units per m² × leaves    To buy = ⌈ Units × (1 + wastage) ⌉

l, h = unit length and height, j = joint thickness (all in metres), leaves = 1 or 2 units across the wall thickness, ⌈ ⌉ = round up.

Worked example

Wall 5 m × 3 m with one door (1.0 × 2.1 m) and two windows (1.2 × 1.2 m); example brick 230 × 110 × 75 mm with 10 mm joints; one brick wide; 5% wastage.

  • Wall area = 15.00 m²; openings = 2.10 + 2 × 1.44 = 4.98 m²; net area = 10.02 m²
  • Module = 0.240 × 0.085 = 0.0204 m² → 49.02 bricks per m²
  • Bricks = 10.02 × 49.02 = 491.2 → with 5%: 515.7 → buy 516

Assumptions and limitations

  • Plain wall without piers, corners or returns. Real requirements also depend on bond pattern, cut units at ends and around openings, breakage and workmanship.
  • The count uses one joint per unit in each direction. Actual joint thickness on site may vary.
  • Mortar quantity is not calculated here — it depends on joint thickness, frogs or cores in the units and the specified mix.
  • Load-bearing masonry must be designed to the applicable code by a qualified person.

References

  • Standard brick-quantity estimating method using the nominal (unit + joint) module.