Brick Calculator

Bricks Needed551
Mortar Bags4
Wall Area80 sq ft

This brick calculator estimates how many bricks and bags of mortar a wall or patio needs. It works from the wall area and the size of a single brick plus the mortar joint width, so the spacing between bricks is properly accounted for. A 5% waste allowance is added for cuts and breakage, and the mortar estimate scales with the brick count.

Formula

bricks = ceil( area × 144 / ((L+J)(H+J)) × 1.05 ); mortarBags = ceil(bricks/1000 × 7)

area
Wall face area in square feet (wall length × wall height)
L, H
Brick length and height in inches
J
Mortar joint thickness in inches
1.05
5% waste allowance for cuts and breakage

How it works

  1. Enter the wall length and height in feet to get the total face area, and enter the brick length, brick height, and mortar joint thickness in inches.
  2. Each brick plus its joint occupies (length + joint) × (height + joint) square inches; dividing 144 by that gives the bricks per square foot, which is multiplied by the wall area.
  3. The raw count is multiplied by 1.05 for 5% waste and rounded up, and mortar is estimated at about 7 bags per 1,000 bricks (rounded up).

Worked example

A 20 ft × 8 ft wall built with standard 8 in × 2.25 in bricks and a 0.375 in mortar joint.

  1. Wall area: 20 × 8 = 160 sq ft.
  2. Bricks per sq ft: 144 / ((8 + 0.375) × (2.25 + 0.375)) = 144 / (8.375 × 2.625) ≈ 6.55.
  3. Raw bricks: 160 × 6.55 ≈ 1,048; add 5% and round up → 1,101 bricks.

About 1,101 bricks and 8 bags of mortar for the 160 sq ft wall.

Frequently asked questions

Why include the mortar joint in the brick size?
Each brick is laid with a mortar gap around it, so the space it actually occupies is the brick dimension plus the joint width. Ignoring the joint would overcount the bricks needed.
How much waste does it allow for?
The calculator adds 5% to the raw brick count to cover cuts at corners and openings plus breakage. For complex layouts with many cuts you may want to order a little extra on top.
How is the mortar estimate calculated?
It assumes roughly 7 bags of mortar per 1,000 bricks and rounds up to whole bags. Actual usage depends on joint thickness, brick absorption, and your mix, so treat it as a guide.
Does it work for patios and pavers?
Yes. Enter the paved area as the wall length and height and use your paver dimensions. For dry-laid patios with no mortar you can ignore the mortar bag figure.