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″ (depth × height × length)
• Actual: 3.625″ × 2.25″ × 7.625″ (same order)
• 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 of wall, by size (all including the 3/8 inch joint):

Queen and King both get called “oversize” at the yard and they are not the same brick. Queen is a standard-length brick that is simply taller. King is longer as well as taller, which is why it drops to under five per square foot. Getting the two confused costs about 20% of the order.

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

How much mortar the joints actually hold. For modular brick at 3/8 inch joints in a single wythe, the joints work out to roughly 20% of the wall volume, which the Brick Industry Association puts at about 7 cubic feet of mortar per 1,000 brick before waste. An 80 lb bag of pre-blended mix yields about 0.6 cubic feet, so one bag covers somewhere near 14 square feet of wall, and a 60 lb bag near 10.5. Those are the figures this calculator and the mortar calculator both use.

Be warned that bag labels do not agree with each other. Some manufacturers print as few as 25 to 30 bricks per bag, which is close to double the mortar the volume math calls for. The label is protecting itself against a heavy hand on the trowel. If you cannot get more of the same batch later, buy toward the label; otherwise the volume figure is closer to what a wall really takes.

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

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 10% waste: 540 × 1.10 = 594 bricks → order 600
• Mortar: 80 sq ft ÷ 14 × 1.10 = 7 bags of 80 lb, or 9 bags of 60 lb
• Materials, at 2026 US ballpark prices: 600 bricks near $0.70 each plus 7 bags near $9 each is roughly $480. Get a real quote, brick pricing moves with freight.

Order the whole wall in one go. Brick colour shifts between production runs, and a section laid from a second lot reads as a patch from across the street.