How to use the brick calculator
- Choose Wall or veneer or Patio or walkway, then enter the length and the height or width in the unit you measured. For a wall, enter the total area of doors and windows to subtract.
- Pick the brick size: modular, engineer, norman, roman, utility or a custom size. Check the joint thickness, which starts at 3/8 inch.
- Choose one brick or two bricks thick for a wall. Keep or change the 10% waste and decide whether the joints are mortared.
- Read the bricks to buy and the mortar bags, then copy the shopping list or add a price per brick.
Formula
Bricks per sq ft = 144 / ((brick length + joint) x (face height + joint))
Bricks = net area x bricks per sq ft x layers
With waste = bricks x (1 + waste percent / 100), rounded up
Mortar per brick = ((length + joint) x (face + joint) - length x face) x depth, in cubic inches
Mortar with extra = mortar x bricks x (1 + extra percent / 100) / 1,728 cubic feet
Bags = mortar with extra / yield per bag, rounded up
Each brick is assumed to take up its own face plus one joint on its right side and one on its top, which is how the 144 square inches in a square foot are divided. The face height is the brick height for a wall and the brick depth for a patio laid flat.
Worked example: a 15 by 8 foot wall of modular brick
A modular brick measures 7.625 x 2.25 x 3.625 inches. With a 3/8 inch joint it occupies (7.625 + 0.375) x (2.25 + 0.375) = 8 x 2.625 = 21 square inches, so a square foot holds 144 / 21 = 6.857 bricks.
The wall is 15 x 8 = 120 sq ft, which needs 120 x 6.857 = 822.9 bricks. With 10% waste that is 905.1, so you buy 906 bricks.
The joint around each brick holds (21 - 17.156) x 3.625 = 13.93 cubic inches of mortar. For 822.9 bricks that is 6.64 cubic feet, or 8.29 cubic feet with 25% extra. At 0.6 cubic feet per bag that is 13.8, so 14 bags.
The same area laid two bricks thick doubles the brick count to 1,645.7, so you would buy 1,811 bricks.
Brick sizes and joints
Bricks are named by their nominal size, which already includes the joint in common practice, but the actual brick is a little smaller. This tool uses the actual brick size and adds the joint you choose, so a different joint gives a different count. A 1/2 inch joint, for example, gives fewer bricks per square foot than a 3/8 inch joint.
If the brick you plan to buy is not in the list, pick a custom size and enter its length, height and depth from the product sheet. Handmade and reclaimed bricks vary, so measure a few before you decide.
Patios, walkways and pattern waste
A patio lays bricks flat, so the wide face of the brick shows. Select the patio option and enter the area. With joints set to zero the bricks are laid tight, as pavers often are. Patterns that need diagonal cuts, such as herringbone at the edges, waste more bricks than a simple running bond, so raise the waste percentage for those layouts.
Mortar, sand and the rest of the job
The mortar estimate assumes the joint is filled across the full depth of the brick, which is on the high side, and then adds an allowance for droppings and mixing waste. Bags are premixed mortar by volume, and site-mixed mortar depends on your mix ratio and is not modeled. Ties, flashing, weep holes, lintels, footings and sealer are separate.
A brick wall that carries a load, supports a roof or sits near a property line is regulated, and its design should come from a qualified professional. This tool counts bricks and mortar and does not check strength.
Assumptions and limits
- Brick sizes shown are common nominal sizes. Real bricks vary by manufacturer and region.
- Every row of bricks follows a simple running pattern. Cuts, arches, soldier courses and patterns with extra cuts are covered only by the waste percentage.
- Mortar assumes full-depth joints and a typical 25% allowance you can edit. A bag yield of 0.6 cubic feet is a typical figure and is editable.
- Openings are entered as one total area in the square of your unit. Window sills and lintels are not modeled.
- Foundations, ties, flashing, expansion joints and engineering are not included.
Frequently asked questions
How many bricks do I need per square foot?
For a standard modular brick with a 3/8 inch joint it is about 6.86 bricks per square foot. Other sizes and joint widths change the number, and the tool calculates it for you.
How do I figure out how many bricks I need for a wall?
Multiply the wall area, minus any openings, by the number of bricks per square foot, then add a waste allowance. A two-brick-thick wall needs twice as many.
How much mortar do I need for 1,000 bricks?
It depends on the brick size and the joint. For modular brick with 3/8 inch joints and full-depth bedding, the formula gives about 8 cubic feet for 1,000 bricks before any extra for waste.
Can I use this for a brick patio?
Yes. Choose the patio option, enter the length and width, and the tool uses the flat face of the brick. Set the joint to zero for tight-laid pavers and untick the mortar box for sand-set bricks.
How much waste should I allow for bricks?
A simple wall often needs around 5 to 10 percent, and patterned or cut-heavy layouts need more. The tool starts at 10 percent and lets you change it.