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Reviewed · Prices checked October 2026 · How we calculate

Brick Calculator: How Many Bricks and Mortar Do I Need?

Enter the wall's length and height and any doors or windows. You get the bricks to buy, the 80 lb bags of mortar mix to lay them, and the cost at your price.

Inputs

Units
ft
ft
sq ft

Total area of doors and windows to leave out.

Brick

Modular is the common US size today (actual 3-5/8 × 2-1/4 × 7-5/8 in). Check the brick's size at the yard.

Extra for waste

5% covers breakage and cuts on a plain wall. Use 10% for lots of corners, openings or cut bricks.

$

Brick prices vary a lot by color and maker, so type your supplier's price.

Shopping list

Updates as you type
567bricks

modular bricks for 80 sq ft of wall, 5% extra

  • 567 bricks—
    Cost appears when you type a price per brick.
  • 16 × 80 lb bags of mortar mix$128–$256
    567 bricks ÷ 37 per bag (QUIKRETE's up-to figure), rounded up.

    Typical price (estimate, checked Oct 2026): $8.00–$16.00 per 80 lb bag of mortar mix

    16 bags × $8.00–$16.00 = $128–$256Estimate
Mortar (type your brick price for the total)$128–$256
Checked Oct 2026

Not included: wall ties, flashing, lintels over openings and the footing. A wall over about 4 ft or one that holds back soil needs your local building code or an engineer.

Show the math
20 × 4 ft − 0 sq ft openings = 80 sq ft80 sq ft × 6.75 bricks per sq ft × 1.05 = 567.0 → 567 bricks567 ÷ 37 = 15.32 → 16 bags of mortar

Mortar prices you type are saved on this device; the brick price is for this estimate only.

How it works

The formula

wall area = length × height − openings
bricks = area × bricks per sq ft × (1 + waste), round up
mortar bags = bricks ÷ 37, round up

Assumptions

  • Bricks per sq ft: 6.75 for modular brick and 6.55 for standard brick, laid in running bond with 3/8 in joints. These are the Brick Industry Association's counts (Technical Note 10, 675 modular bricks per 100 sq ft), before waste.
  • The wall is one brick thick (a single wythe, like a veneer or garden wall). For a double wall, double the bricks and mortar.
  • Mortar: one 80 lb bag of QUIKRETE Mortar Mix lays up to 37 standard bricks, so we divide the bricks you buy by 37. Messy joints or a beginner's hand use more; an extra bag is cheap insurance.
  • Openings are taken off before waste is added.

Worked example

A 20 ft long, 4 ft high garden wall, modular brick, 5% waste

  1. Wall: 20 × 4 = 80 sq ft
  2. 80 × 6.75 × 1.05 = 567.0 → 567 bricks
  3. 567 ÷ 37 = 15.32 → 16 bags of mortar

Bricks by wall size

Modular bricks and 80 lb bags of mortar by wall size, 5% waste
WallBricksMortar bags
10 × 3 ft2136
20 × 4 ft56716
30 × 6 ft1,27635
40 × 8 ft2,26862

Modular brick, no openings, 5% extra.

Questions people ask

How many bricks are in a square foot?

About 6.75 modular bricks or 6.55 standard bricks per sq ft of wall with 3/8 in mortar joints, before waste. That's 675 modular bricks per 100 sq ft.

How many bricks does a bag of mortar lay?

QUIKRETE says an 80 lb bag of Mortar Mix lays up to 37 standard bricks. Real walls often get fewer, so round up and keep a spare bag.

How many bricks for a 10 × 10 ft wall?

100 sq ft × 6.75 = 675 modular bricks, or 709 with 5% extra, and 20 bags of mortar.

How much does a brick cost?

It ranges widely: common clay bricks can be under a dollar each at a home center, while face brick from a brick yard is priced by the thousand and depends on color and maker. Type your supplier's price for the total.