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Brick Calculator

Ordering bricks is a guessing game without a number to work from: too few and the wall stops half built while you wait for another delivery; too many and you have a pallet of bricks sitting in the yard for years. Enter your wall area in square feet and this free brick calculator tells you how many standard bricks to order, with 10% waste, and how many bags of mortar the job needs.

Common brick jobs

How it works

A standard brick is about 8 inches long, 3⅝ inches wide, and 2¼ inches high, and it is laid with a mortar joint of about ⅜ inch around it. Once the joints are counted, one brick plus its share of mortar covers roughly one seventh of a square foot — which is why the standard estimating rate is 7 bricks per square foot of wall. That rate is for a single layer of brick, one brick thick, laid in the usual running bond pattern where each course is offset by half a brick so the vertical joints never line up. A double-thick wall needs twice as many bricks, so if your wall is two bricks thick, double the answer this calculator gives.

The calculation itself is simple: multiply the wall area by 7 to get the exact brick count, then add the waste allowance and round up to a whole brick. For 100 square feet, that is 100 × 7 = 700 bricks, plus 10% waste (700 × 1.10 = 770), and 770 is already a whole number. The waste allowance is not padding for the sake of it. Bricks break — in the pallet on the truck, when they are dropped, and when they are cut with a bolster or a saw to fit around an opening or a corner. A wall with a window in it, or a wall that steps around a corner, wastes more than a long straight wall, so choose 15% for fiddly work. And remember that bricks are usually sold by the pallet of about 500, so an order of 770 bricks is two pallets with some left over — the leftover bricks are worth keeping, because matching the exact colour of a brick batch months later is never guaranteed.

Mortar is estimated separately, at about one 60-pound bag per 30 square feet of wall. A bag of mortar mix, once water is added, fills the joints between the bricks and beds each course level. For 100 square feet, 100 ÷ 30 = 3.33, rounded up to 4 bags. Like the bricks, mortar is rounded up to whole bags because part of a bag cannot be bought — and an opened bag of mortar mix does not keep, so it is better to have one spare sealed bag than to run out with three courses left to lay. Mortar use also rises on a rough or uneven wall, where the joints end up thicker than planned, and in hot, dry weather, where mortar dries faster and more is wasted. If you are laying bricks in summer, keep an extra bag on hand.

Measuring the wall is the step that decides whether the answer is right. Measure the length of each wall and multiply by its height, then add the walls together. A garden wall 20 feet long and 5 feet high is 100 square feet. For a house wall, measure the full rectangle first, then subtract every opening: a door 3 feet by 7 feet takes off 21 square feet, and a window 4 feet by 5 feet takes off 20. If you forget to subtract the openings, you will over-order — which is the safe direction, but it costs money. If you forget a whole wall, you will under-order, which costs time. Walk around the job, list every wall and every opening on paper, and only then enter the total.

One last check before ordering: the brick itself. The 7-per-square-foot rate fits the standard brick described above. Larger bricks — sometimes called jumbo or modular bricks — cover more area each, so the rate drops; smaller or handmade bricks cover less, so the rate rises. The calculator lets you change the bricks-per-square-foot figure, so if your supplier quotes a different rate for the brick you have chosen, enter it and the answer will follow. When in doubt, ask the supplier how many of their bricks make a square foot, and use their number — they know their own product.

Worked example

Priya is building a garden wall 20 feet long and 5 feet high. There are no doors or windows in it, so the wall area is the full rectangle.

Step 1: Find the wall area: 20 × 5 = 100 square feet.
Step 2: Find the exact brick count: 100 × 7 = 700 bricks.
Step 3: Add 10% waste: 700 × 1.10 = 770 bricks.
Step 4: Find the mortar: 100 ÷ 30 = 3.33, rounded up to 4 bags of 60 lb mortar.

Priya orders 770 bricks and 4 bags of mortar. At about 500 bricks per pallet, that is two pallets delivered, with the spare bricks kept for repairs. If the same wall were two bricks thick, she would double the order to 1,540 bricks and 8 bags of mortar.

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