Brick Calculator

Brick quantity and mortar estimation are fundamental for any masonry project — walls, patios, fireplaces, and facades. The calculation requires knowing the wall area, brick size, mortar joint thickness, and accounting for waste.

Number of bricks formula: Bricks Needed = (Wall Area ÷ Face Area of One Brick) × Waste Factor

Face area per brick: Face Area = (Brick Length + Joint Thickness) × (Brick Height + Joint Thickness)

Standard brick dimensions (US modular brick):

• Nominal: 4″ × 2.67″ × 8″ (height × depth × length)
• Actual: 3.625″ × 2.25″ × 7.625″
• Standard mortar joint: 0.375″ (3/8 inch)
• Modular face area (with joint): 8″ × 2.67″ = 21.33 sq in = 0.148 sq ft per brick

Bricks per square foot (standard US modular): approximately 6.75 bricks/sq ft (including mortar joints)

Waste factor:

• Straight wall: add 5–7%
• Curved walls: add 10–15%
• Complex patterns (herringbone, diagonal): add 15–20%
• Allow 5% for cutting at window/door openings

Mortar quantity formula: Mortar (cubic feet) = Wall Volume × Mortar Fraction

Mortar occupies approximately 25–30% of total wall volume in standard brick construction.

Mortar mix ratio (Type S — general purpose masonry):

• 1 part Portland cement : 0.5 part lime : 4.5 parts masonry sand
• Yield per 94 lb bag of Portland cement: approximately 2.5 cubic feet of mortar

Pre-mixed mortar coverage:

• One 60 lb bag of mortar mix: covers approximately 25–30 bricks laid with 3/8″ joints

Worked example: Building a garden wall: 20 feet long, 4 feet tall, single wythe (one brick deep = 4″ thick).

• Wall area: 20 × 4 = 80 sq ft
• Bricks needed (6.75/sq ft): 80 × 6.75 = 540 bricks
• Add 7% waste: 540 × 1.07 = 578 bricks → order 580
• Mortar bags (1 bag per 25–30 bricks): 580 ÷ 27 = ~22 bags of mortar mix
• Cost estimate: 580 bricks × $0.70/brick + 22 bags × $8 = $406 + $176 = ~$582 in materials

Always buy 10% more than estimated — running short mid-project means color/lot mismatches between batches.