Brick Calculator

Enter your wall dimensions, mortar joint width, and brick size to calculate the total number of bricks and bags of mortar needed. Includes a waste factor for cuts and breakage.

What is Brick?

A brick calculator determines how many bricks and how much mortar are required to build a wall of a given size. Accurate brick estimation prevents costly over-ordering (bricks are heavy and expensive to return) and project-stopping shortages that can delay work while waiting for a matching batch from the supplier. The calculation is based on the concept of a "unit" — one brick plus one mortar joint. A standard modular brick measures 8 inches long by 2-1/4 inches tall by 3-5/8 inches deep. With a standard 3/8-inch mortar joint, the unit dimensions are 8-3/8 inches wide by 2-5/8 inches tall. The number of bricks per square foot is found by dividing 144 (the number of square inches in a square foot) by the area of one unit on the wall face. For standard modular bricks with 3/8-inch joints, this works out to approximately 6.55 bricks per square foot. Mortar consumption depends on the brick size and joint width. The industry standard estimate is one 80-pound bag of Type S or Type N mortar mix for every 35 standard bricks. This accounts for both the bed joints (horizontal) and head joints (vertical) in a single-wythe (one brick thick) wall. The waste factor accounts for bricks that crack during cutting, break during handling, or are rejected for visual defects. A 5% waste factor is standard for walls with few openings and straight runs. Increase to 10% for walls with many cuts around windows, arches, or decorative patterns. Salvage and reclaimed brick projects may need 15-20% waste allowance due to higher breakage rates. Brick sizes vary by region and style. While the standard modular brick is most common in North American construction, other sizes include queen (7-5/8 x 2-3/4 inches), king (9-5/8 x 2-5/8 inches), and utility (11-5/8 x 3-5/8 inches). The calculator accepts custom brick dimensions to handle any size accurately. For walls with openings, subtract the area of each window and door before calculating. A standard door opening is about 21 square feet and a standard window is about 15 square feet.

How to Calculate

1. Measure the total wall length in feet
2. Measure the wall height in feet
3. Confirm the mortar joint width (3/8 inch is the standard for modular brick)
4. Enter the brick length and height in inches (8 x 2.25 for standard modular)
5. Set the waste factor (5% for simple walls, 10% for walls with many openings)
6. Review total bricks needed and mortar bags required
7. Subtract area for any windows or doors to refine the estimate

Formula

Wall Area = Wall Length (ft) x Wall Height (ft) Unit Width = Brick Length (in) + Mortar Joint (in) Unit Height = Brick Height (in) + Mortar Joint (in) Bricks per Sq Ft = 144 / (Unit Width x Unit Height) Total Bricks = ceiling(Wall Area x Bricks per Sq Ft x (1 + Waste Factor / 100)) Mortar Bags = ceiling(Total Bricks / 35) Where 144 is the number of square inches per square foot, and 35 bricks per bag is the standard mortar coverage for 80-lb bags with standard modular bricks.

Example Calculation

A 20 ft x 8 ft wall with standard modular bricks (8 x 2.25 in) and 3/8-inch mortar joints at 5% waste: Wall Area = 20 x 8 = 160 sq ft Unit Width = 8 + 0.375 = 8.375 in Unit Height = 2.25 + 0.375 = 2.625 in Bricks per Sq Ft = 144 / (8.375 x 2.625) = 144 / 21.98 = 6.55 bricks Bricks Raw = 160 x 6.55 = 1,048 bricks Total Bricks = ceil(1,048 x 1.05) = 1,101 bricks Mortar Bags = ceil(1,101 / 35) = 32 bags

Frequently Asked Questions