Brick and Mortar Quantity Calculator
The number of bricks in a wall is the wall face area divided by the area one brick occupies, where each brick is counted with its mortar joints. The repeating unit is the brick face length plus one joint, by the brick face height plus one joint. This calculator computes bricks per square foot from your exact brick and joint sizes, scales by wall area and wythes, adds waste, and then estimates mortar bags from the yield published by your mortar maker. Brick sizes and bag yields vary, so they are user inputs to keep the figure honest.
Brick and mortar formula
Unit area (sq in) = (length + joint) * (height + joint)
Bricks per sq ft = 144 / unit area
Base bricks = bricks per sq ft * area * wythes
Bricks needed = ceil(base bricks * (1 + waste% / 100))
Mortar bags = ceil(bricks needed / bag yield)
Adding the joint to both brick dimensions gives the true repeating cell. There are 144 square inches in a square foot. Wythes multiply the count for multi-layer walls, and bag yield comes from your mortar product data.
Brickwork context
- Each brick in a wall occupies its face size plus one mortar joint in each direction.
- A modular brick face is about 8 by 2.25 inches; a standard joint is 3/8 inch.
- A wythe is one brick-thick layer; double-wythe walls need roughly twice the material.
- Bag yield (bricks per bag) is set by your mortar mix and joint size, so read the bag.
- Allow 5 to 10 percent waste for breakage, cuts, and color blending across pallets.
Brick and mortar: frequently asked questions
How many bricks do I need per square foot?
Divide one square foot by the area each brick face occupies including its mortar joints. A modular brick face of 8 by 2.25 inches with a 3/8-inch joint occupies about (8.375 by 2.625) inches, so roughly 6.4 bricks cover a square foot. This calculator works it out from the brick and joint sizes you enter so it matches your exact brick.
Why include the mortar joint in the brick size?
Because in a finished wall each brick is surrounded by mortar, so the repeating unit is the brick face plus one joint width and one joint height. Using only the bare brick size overstates the brick count, since it ignores the space the mortar takes up. Always add the joint thickness to both dimensions.
How much mortar do I need?
Mortar use depends on brick size, joint thickness, wall thickness (single or double wythe), and waste. Bag yield (bricks laid per bag) is published by the mortar maker and varies with mix and joint size, so enter your product's figure. This calculator divides total bricks by that yield and rounds up.
What is a wythe?
A wythe is a single continuous vertical layer of masonry one unit thick. A single-wythe wall is one brick thick; a double-wythe wall is two. Doubling the wythes roughly doubles both the bricks and the mortar for the same wall face area, so confirm your wall thickness before ordering.
How much waste should I allow?
Allow extra for breakage, cuts at openings and corners, and color blending across pallets. A 5 to 10 percent waste allowance is common for brick. This tool applies the waste percentage you enter to the brick count, then rounds up to a whole number of bricks.
Official sources
- International Code Council: International Residential Code (masonry construction).
- U.S. National Institute of Standards and Technology: NIST Unit Conversion (length and area units).
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.