Brickwork & Block Masonry Calculator (First Party)
Calculate brick count, mortar volume, cement bags, and sand for any masonry wall by length, height, thickness, brick size, and mortar ratio.
Wall dimensions
Brick / block dimensions
Mortar
How this works
We pack rectangular cells of one brick plus its half-share of mortar joint into the wall volume, then back-figure the mortar volume:
wallVol = L × H × t
actualBrickVol = bL × bW × bH
brickWithMortar = (bL+j) × (bW+j) × (bH+j)
bricks = ceil(wallVol / brickWithMortar)
mortarVol = wallVol − bricks × actualBrickVol
dryMortar = mortarVol × 1.30
cementVol = dryMortar × c / (c + s)
sandM3 = dryMortar × s / (c + s)
cementBags = ceil(cementVol / 0.0347)The 1.30 factor is the dry-volume bulking allowance for masonry mortar — slightly higher than plaster's 1.27 because the joint pocket is three-dimensional, not a thin coat.
Worked example
10 m × 3 m, half-brick wall (0.115 m), 200 × 100 × 100 mm bricks, 12 mm joint, 1:6 mortar:
- Wall volume =
10 × 3 × 0.115 = 3.45 m³ - Brick-with-mortar cell ≈
0.212 × 0.112 × 0.112 ≈ 0.00266 m³ - Bricks ≈ ceil(3.45 / 0.00266) ≈ 1,298
- Mortar ≈
3.45 − 1,298 × 0.002 ≈ 0.85 m³ - Cement ≈ ceil((0.85 × 1.30 × 1/7) / 0.0347) ≈ 5 bags
- Sand ≈
0.85 × 1.30 × 6/7 ≈ 0.95 m³
Sources
- IS 1077 (Common Burnt Clay Building Bricks) and field-practice masonry mortar bulking factor (1.30)
FAQ
What is the difference between a half-brick and a single-brick wall?
A half-brick wall is 115 mm thick (0.115 m) — the brick laid on its long edge — and is used for partition walls and interior dividers. A single-brick wall is 230 mm (0.23 m) — the brick laid on its broad face — and is the standard external wall thickness for a load-bearing or infill brick wall in South Asia. The calculator scales the brick count and mortar volume linearly with whatever wall thickness you enter, so both options work.
Why is the brick-with-mortar volume larger than the brick alone?
Each brick sits in a thin envelope of mortar — typically 10 to 12 mm on each face. When packing the wall we are really packing rectangular cells made of one brick plus its half-share of the surrounding joint. The calculator computes the cell volume as (brickL + joint) × (brickW + joint) × (brickH + joint), so the count = wall volume / cell volume already includes the mortar gap. The actual mortar volume is the leftover wall volume after subtracting the bricks themselves.
Which mortar mix ratio should I use for masonry?
1:6 (cement:sand) is the conventional masonry mortar for residential brickwork — leaner, cheaper, and adequate for non-load-bearing infill. 1:5 is used for one- and two-storey load-bearing walls. 1:4 is reserved for the bottom three to four courses of a masonry wall (the plinth band) and for parapet copings exposed to weather. 1:3 is high-strength mortar used only for repair grouting or special details — it is too rich for general bricklaying.
Why is the dry-mortar volume 1.30 times the wet volume?
Mortar bulks slightly more than thin-coat plaster because the joint volume is not a flat film — it is a three-dimensional pocket between rough brick faces. We use 1.30 (a 30 percent bulking allowance) for masonry mortar dry-volume sizing. This is the field-practice convention; it sits between IS 456's 1.54 for cast concrete and the 1.27 used for thin plaster.
How accurate is the brick count?
The covering invariant guarantees that the bricks plus mortar fill the wall — but it is an upper bound (we round up to the nearest whole brick). Real construction loses 3–8 percent of bricks to cutting at openings and corners, plus breakage in transit. For procurement, multiply the calculator's brick count by 1.05 to 1.10 for a small wall and by 1.08 to 1.10 for a multi-storey building.
Can I use this for concrete blocks instead of clay bricks?
Yes. Enter the block dimensions in the brick-size fields — for example 400 × 200 × 200 mm becomes 0.40 × 0.20 × 0.20 m — and the calculator handles them identically. Concrete blocks generally use a 1:5 or 1:6 mortar mix and a 10 mm joint. AAC blocks use thin-bed mortar (typically 3 mm) which the calculator can also model with a small joint value.