Brick Calculator
Bricks for a single-layer wall, from the wall size, brick size and mortar joint.
The math
Each brick occupies its own footprint plus one mortar joint on two sides, so the wall area is divided by (length + joint) × (height + joint). A US modular brick with a 3/8-inch joint covers exactly 8 × 2.67 inches, about 6.75 bricks per square foot; UK bricks with a 10 mm joint run 60 per square meter. This is for a single-wythe (half-brick) wall; double it for a solid double-thickness wall.
Mortar and extras
Figure roughly one 80 lb (36 kg) bag of mortar per 100 to 140 bricks; the estimate here uses 125. Waste covers broken bricks and cut ends at corners and openings, and like tile, brick color varies by batch, so buy the spares up front. Openings you can subtract yourself: a standard door is about 20 sq ft, a window 8 to 12.