Brick Calculator Formula

Understand the math behind the brick calculator. Each variable explained with a worked example.

Formulas Used

Wall Area

wall_sqft = wall_area

Bricks (no waste)

bricks_no_waste = ceil(wall_area / brick_face_area)

Bricks (with waste)

bricks_with_waste = ceil(wall_area / brick_face_area * (1 + waste_percent / 100))

Variable	Description	Default
`wall_length`	Wall Length(feet)	20
`wall_height`	Wall Height(feet)	8
`brick_length`	Brick Length(inches)	8
`brick_height`	Brick Height(inches)	2.25
`mortar_joint`	Mortar Joint Width(inches)	0.375
`waste_percent`	Waste Factor(%)	7
`wall_area`	Derived value`= wall_length * wall_height`	calculated
`brick_face_area`	Derived value`= ((brick_length + mortar_joint) / 12) * ((brick_height + mortar_joint) / 12)`	calculated

Bricks = Wall Area / Brick Face Area × (1 + Waste%)

Brick face area includes the mortar joint on one side and the top:

Brick Face Area = (Brick Length + Mortar) × (Brick Height + Mortar)

A standard modular brick is 8" × 2-1/4" with a 3/8" mortar joint. This gives approximately 6.75 bricks per square foot of wall.

A wall 20 ft long and 8 ft high with standard modular bricks (8" × 2.25") and 3/8" mortar joints, 7% waste.

wall_length = 20wall_height = 8brick_length = 8brick_height = 2.25mortar_joint = 0.375waste_percent = 7

01Wall area = 20 × 8 = 160 sq ft
02Brick face area = (8 + 0.375)/12 × (2.25 + 0.375)/12 = 0.698 × 0.219 = 0.1528 sq ft
03Bricks needed = 160 / 0.1528 = 1,047 bricks
04With 7% waste = 1,047 × 1.07 = 1,121 bricks

Ready to run the numbers?