Concrete Block Wall Calculator
Enter wall length, height, thickness and block size (default 390×190×190 mm) with mortar joint to estimate total blocks and mortar volume for a hollow concrete block wall.
Input Data
Results
At a glance:A concrete block wall is laid in three dimensions: blocks per course = ⌊wall length ×1000 ÷ (block length + joint)⌋, courses = ⌊wall height ×1000 ÷ (block height + joint)⌋, through-thickness blocks = ⌊thickness ÷ (block width + joint)⌋ (minimum 1). Total blocks = product of the three; block solid volume = total blocks × single block solid volume. Mortar volume = wall volume − total block solid volume. This calculator uses the block width (190 mm) as the thickness direction, suitable for standard hollow concrete blocks.
Formula
Blocks per course = ⌊L×1000/(block length+joint)⌋
Courses = ⌊H×1000/(block height+joint)⌋
Through-thickness blocks = ⌊T/(block width+joint)⌋
Total blocks = per course × courses × through
Mortar = wall volume − total blocks × block solid volume
$$n_L = \left\lfloor \frac{L\cdot1000}{l+j} \right\rfloor$$$$n_H = \left\lfloor \frac{H\cdot1000}{h+j} \right\rfloor$$$$n_T = \left\lfloor \frac{T}{w+j} \right\rfloor$$$$N = n_L\,n_H\,n_T$$$$V_m = V_w - N\,v_b$$How to Use
- Enter wall length, height and thickness (mm).
- Confirm the block size (default 390×190×190) and mortar joint.
- The tool outputs wall volume, total blocks and mortar volume.
Case Studies
Partition wall
4×3 m, 190 mm thick, block 390×190×190, joint 10 mm.
10 per course, 15 courses, 1 through; about 150 blocks; mortar about 0.18 m³.
Double-course exterior wall
5×3 m, 390 mm thick.
2 through; about 300 blocks; mortar about 0.5 m³.
FAQ
How does this differ from the brick wall calculator?
This uses hollow concrete blocks (390×190×190) rather than standard bricks (215×102.5×65); sizes and single-block volume differ, suiting different wall types.
How is hollow block volume counted?
This calculator estimates mortar from the block's outer solid volume, not subtracting the hollow cores; actual mortar is slightly less, so add about 5% wastage as buffer.
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References
Content review: Calculatorism Construction Team. Results are for reference only; please refer to the relevant authorities for the official figures.