Bricks per square foot, then multiply by wall area
Work in the brick's face dimensions plus the mortar joint. A US modular brick is 8 in × 2.25 in; with a 3/8 in joint its effective face is 8.375 × 2.625 = 21.98 in². Dividing into 144 gives 6.55 bricks per square foot. Multiply by your wall area, then add a waste margin.
Bricks per unit area by size
Larger bricks mean fewer per square foot. Enter your actual brick dimensions, since manufacturers vary.
| Brick | Face size | Per ft² | Per m² |
|---|---|---|---|
| US modular | 8 × 2.25 in | 6.55 | ~70 |
| Standard (US) | 7.625 × 2.25 in | 7.0 | ~75 |
| UK standard | 215 × 65 mm | — | ~60 |
| Norman | 10 × 2.25 in | 4.5 | ~48 |
All figures include a standard 3/8 in (10 mm) mortar joint.
The three things that change the count
- Wall thickness. A single-wythe wall is one leaf of brick; a double-wythe or cavity wall is two, so it needs twice the bricks for the same face area.
- Waste factor. Add 5 to 10% for straight runs, 10 to 15% for many cuts, and up to 20% for arches or herringbone. Buy extra from the same batch to keep the color matched.
- Bond pattern. Running, English and Flemish bonds use practically the same brick count; only stack bond adds a few percent from extra cutting. Bond mostly affects looks and strength, not quantity.
Common questions
How many bricks do I need for 100 square feet?
For a standard modular brick with a 3/8 inch mortar joint you get about 6.55 bricks per square foot, so 100 square feet needs roughly 655 bricks. Add 10% for cuts and breakage and order about 720.
Do I count the mortar joint in the brick size?
Yes. Add the joint thickness to both the length and height before dividing into the wall area. Using the bare brick size instead makes you buy 2 to 3% too many bricks.
How much mortar do I need per brick?
A rough field rule is one 25 kg bag of mortar for every 50 bricks. So 700 bricks needs about 14 bags.
