Brick and Block Calculator

Enter the wall and unit sizes to get the number of units, the wall volume and the mortar.

How the calculator works

By volume: units = wall volume ÷ unit volume including the joint. The method works for bricks, large blocks and any wall thickness.

Worked example

A wall 10 × 3 m, 380 mm thick, minus 6 m² of openings. Wall volume: (30 − 6) × 0.38 = 9.12 m³. A single brick 250 × 120 × 65 mm with a 10 mm joint takes 0.00234 m³. That gives about 3,900 bricks, plus 5% waste ≈ 4,100.

Common sizes

What the calculator does not include

• Reinforcement. Masonry is reinforced every 3–4 courses, and always under windows and above openings.
• Lintels. Openings need precast or cast-in-place lintels.
• Delivery breakage. Allow 3–5% for palletised brick; blocks break less often but corners chip easily.

Aerated blocks laid on adhesive foam use a 2–3 mm joint: the block count barely changes, while mortar and cold bridges drop sharply.

🧰Construction Material Calculators

Updated: 2026-09-18