Brick Calculator: How Many Bricks Do I Need?

How to measure a brick wall

1. Measure the length in feet along the base of the wall. For a wall with corners, add up the runs but count each corner only once. Divide inches by 12 to get feet (20 ft 6 in is 20.5 ft).
2. Measure the height in feet from where the brick starts, such as the top of the footing, to where it stops, such as the wall cap or soffit. For a triangular gable, enter its width as the length and half its peak height as the height, then add that count to the main wall.
3. Add up the openings. Multiply the width by the height of each door, window, and vent, and enter the total in "Doors and windows to subtract." A 3 × 7 ft door is 21 sq ft. BIA's wall-area method works from the net wall area: the gross area less the openings.
4. Confirm the brick size. Check the specified size on the product sheet or measure a brick, and pick the option whose face (length × height) matches. Depth doesn't change the count for a wall one brick thick. For a wall of 8 × 16 in concrete block, use the concrete block calculator.
5. Pick the mortar joint. The default is 3/8 in: a modular brick's 7 5/8 in length plus a 3/8 in joint makes its 8 in nominal length. Choose 1/2 in if your plans or existing brickwork call for it.
6. Enter your bag yield and extra. Use the "bricks per bag" figure on your mortar bag, and keep the extra at 5 percent or more. BIA notes that job conditions may warrant a higher percentage.

Bricks per square foot by brick size

The seven sizes in the calculator, from BIA Technical Note 10, Table 4 (running bond, no waste added):

BIA notes that a brick's name and size can vary by region and by manufacturer, and it gives ranges for some sizes: queen brick can be 7 5/8 or 8 in long, and king brick 9 5/8 to 9 3/4 in long. If your brick doesn't match a row, ask the supplier how many it takes per square foot. For a patio or walkway of 4 × 8 in pavers, use the paver calculator.

Modular brick per square foot: 6.75 or 6.86?

6.75 modular bricks per square foot is the Brick Industry Association's count, and it's the one the calculator uses. Some manufacturer charts, such as Glen-Gery's, list 6.86, because they add a 3/8 in joint to the brick's 2 1/4 × 7 5/8 in face: 144 ÷ (8 × 2 5/8) = 6.86. BIA counts by nominal size instead: three courses of modular brick rise 8 in, so each course takes 2 2/3 in, and 144 ÷ (8 × 2 2/3) = 6.75. Both methods for each size in the calculator:

For modular brick the gap is 1.6 percent, about 107 bricks per 1,000 sq ft before extra, well inside the 5 percent extra. It's bigger for queen and king brick, because BIA's 5.5 and 4.55 work out for the larger sizes in their ranges, an 8 in queen and a 9 3/4 × 2 3/4 in king, while the calculator's options show the shorter faces. To match the face-plus-joint count with 5 percent extra, enter 7 percent extra for modular, 10 for a 7 5/8 in queen, and 11 for a 9 5/8 × 2 5/8 in king: 1,000 sq ft then comes to 7,223, 6,050, and 5,051 bricks.

Brick sizes chart, from modular to king

12 brick sizes from BIA's Technical Note 10, from Roman brick (2 in nominal height, 6 per square foot) to utility brick (4 × 4 × 12 in nominal, 3 per square foot). Specified sizes are width × height × length for a 3/8 in joint; nonmodular brick has no nominal size, and BIA gives a range where makers differ:

The specified size is what the brick is made to, before mortar; the nominal size adds the joint, so modular brick lines up with walls laid out in 4 and 8 in steps. Coursing tells you how many rows reach a height: modular, Norman, and standard brick rise 8 in every 3 courses, or 4.5 courses per foot. The mortar column is BIA's theoretical volume in the joints, before the 15 to 25 percent it says to add for waste. The calculator covers 7 of these sizes; for Roman, closure, or engineer Norman brick, multiply the net wall area by the count above ÷ 100. Cut pieces aren't separate sizes: BIA calls a piece of brick, usually half the length or smaller, a bat, and a brick cut to a nominal 2 in face a queen closer, and it says to include partial brick in the estimate where cuts keep the bond at corners.

How many bricks in a wall: common sizes

Modular brick, 3/8 in joints, 5 percent extra, and 37 bricks per bag, straight from the calculator:

Brick veneer vs. a double wythe wall

13.5 modular bricks per square foot for a double wythe wall, twice the 6.75 of brick veneer, which is a single wythe (one brick thick). Per 100 sq ft of wall, before extra, for the 4 in brick sizes:

Two wythes of 3 5/8 in brick with a 3/8 in collar joint, the vertical joint between them, make a 7 5/8 in wall, 8 in nominal. BIA adds 3.13 cu ft of mortar per 100 sq ft for a 3/8 in collar joint mortared solid (4.17 for 1/2 in) on top of each wythe's joints, so a modular wall with 1/2 in joints takes about 18.0 cu ft. The calculator counts one wythe: run it once for each wythe and add the collar joint. A double wythe wall that carries load or holds back soil needs a qualified professional's design.

Anchored brick veneer over wood studs is a nominal 3 or 4 in wythe tied to the framing, with at least a 1 in air space behind it. BIA's veneer note calls for at least one tie per 2.67 sq ft of wall, spaced no more than 32 in apart horizontally and 24 in vertically; a tie on every 16 in stud every 24 in up covers exactly 2.67 sq ft. That's about 38 ties per 100 sq ft, or 60 for the 160 sq ft example wall.

Tips and common mistakes

• Skipping the openings, or subtracting them twice. Enter the total area of doors and windows once. Leaving out a garage door or large windows can add hundreds of bricks.
• Cutting the extra too thin. BIA's general rule is at least 5 percent over the net brick quantity. Raise it for walls with many corners, openings, or cut brick.
• Assuming every brick is the same size. Check the specified size, the brick itself without the joint, before you pick an option. The example wall in queen brick takes 924 bricks, not 1,134.
• Ignoring the joint size. A 1/2 in joint needs more mortar than 3/8 in: 6.9 vs. 5.5 cu ft per 100 sq ft for modular brick. Match your plans or the brickwork you're adding to.
• Buying brick in batches. BIA's brick selection note says it is best to purchase all brick from the same production run, because there are typically slight color variations between runs. Order the full quantity, extra included, at once.
• Laying one cube at a time. Color can occasionally vary within a run too, so BIA recommends mixing straps of brick from different cubes around the wall as you lay.

Estimates only: when to call a pro

This calculator estimates material for non-structural work such as brick veneer, garden walls, and planters. The count doesn't include the footing or foundation; the concrete calculator turns a footing's size into cubic yards and bags. Load-bearing walls, retaining walls, chimneys, and fireplaces need a qualified professional and your local building code. For example, under the 2015 IRC (section R404.4), a retaining wall not supported at the top that holds back more than 48 in of unbalanced fill must be designed using accepted engineering practice, and so must one over 24 in high that resists loads beyond the soil.