How many bricks per square foot — and per m²?
Each brick occupies its face plus its share of the mortar joints, so the count divides wall area by the jointed face:
bricks = net wall area ÷ ((length + joint) × (height + joint)) × wythes × (1 + waste)
modular, 3/8″ joint: 8″ × 2.625″ = 21 in² → 6.86 bricks / ft²
So a modular-brick veneer runs about 7 bricks per square foot. The UK metric brick at a 10 mm joint covers 225 × 75 mm = 0.0169 m², about 59–60 bricks per square metre in a half-brick (single-wythe) wall — the figure every UK guide quotes, and it falls straight out of the geometry.
Brick sizes
Generic dimensional conventions — actual production sizes vary by region and maker, so measure a unit from your pallet for anything precise. Per-area figures are computed at a 3/8″ (10 mm) joint.
| Brick | L × H × W | per ft² | per m² |
|---|---|---|---|
| Modular | 7-5/8 × 2-1/4 × 3-5/8″ | 6.86 | 73.8 |
| US standard | 8 × 2-1/4 × 3-5/8″ | 6.55 | 70.5 |
| Queen | 9-5/8 × 2-3/4 × 3-1/8″ | 4.61 | 49.6 |
| King | 9-5/8 × 2-5/8 × 2-3/4″ | 4.80 | 51.7 |
| UK metric | 215 × 65 × 102.5 mm | 5.51 | 59.3 |
How much mortar per brick — and per 100 bricks?
Honest mortar math is the jointed envelope minus the brick: ((L+j)(H+j) − LH) × bed width. For a modular brick at 3/8″ that’s about 13.9 in³ per brick — roughly 0.8 ft³ of wet mortar per 100 bricks, so an 80 lb bag yielding ~0.66 ft³ lays in the neighborhood of 80–120 bricks depending on joint and unit. That lines up with the masonry rule of thumb of 5–7 bags per 1,000 bricks. Frogs and cores soak up extra, which is why the bag-yield field is editable and the result rounds up.
Sand and cement instead of bagged mortar
Field mixing splits the mortar volume at your ratio — the textbook masonry mix is 1 part cement to 3 parts sand. The calculator multiplies the wet volume by a 1.3 dry-volume factor, splits it by the ratio, and reports cement in 94 lb bags (≈1 ft³ each) and sand in tons. A useful cross-check from the same geometry: 1,000 modular bricks take roughly 8 ft³ of wet mortar ≈ 0.4 tons of sand and 2–3 cement bags at 1:3.
A 9-inch brick wall (double wythe)
A solid one-brick-thick wall — the international “9-inch wall,” two 102.5 mm wythes plus the collar joint — simply doubles the brick count and mortar for the same face area: 120 bricks per m² with the metric brick. Pick double wythe in the wall-thickness selector and the math follows.
Repointing mortar calculator
Repointing replaces only the outer joint, so the volume is joint length × joint width × raking depth. The repointing tab derives the joint length per square foot from your brick face (each brick contributes about one bed and one head joint), multiplies by the ~3/4″ raking depth, and returns the mortar volume and bags — typically a surprisingly small number, which is why repointing is sold by labor, not material.