How to Calculate Bricks
Estimating bricks starts with the wall area, divided by the face area of a single brick plus mortar joints. Most residential brickwork uses modular bricks with 3/8 inch mortar joints, yielding about 7 bricks per square foot. Add a waste factor for cuts, corners, and breakage.
Brick Count Formula
Bricks=Wall Area×Bricks per sq ft×(1 +Waste%)
Mortar Bag Formula
Mortar Bags=Brick Count45
Rule of thumb: one 80 lb bag of Type N or S mortar sets roughly 45 modular bricks with 3/8 in joints. For 700 bricks that is about 16 bags, or 9 cu ft of mortar.
Common Brick Types and Coverage
| Type | Face Size | Bricks / sq ft |
|---|---|---|
| Modular | 8 x 2-2/3 in | 7.0 |
| Standard | 8 x 2-1/4 in | 6.75 |
| Queen | 8 x 2-3/4 in | 5.75 |
| King | 10 x 3 in | 4.8 |
| Oversize / Utility | 12 x 4 in | 3.0 |
Mortar Required
Plan on about one 80 pound bag of Type N or Type S mortar for every 40 to 50 modular bricks. For a 100 sq ft wall with 700 modular bricks, that is roughly 14 to 18 bags, or about 9 cubic feet of mortar.
Brick Bonds (Patterns)
- Running bond - most common, each brick offset 1/2 from course below
- Stack bond - all bricks aligned vertically; decorative, weakest
- Flemish bond - alternating stretchers and headers; traditional, labor-intensive
- English bond - alternating courses of all stretchers and all headers; historic
- Herringbone - 45 degree pattern for floors, pavements, decorative panels
Brick Grades and Exposure
| Grade | Exposure | Min Strength |
|---|---|---|
| SW (severe weathering) | Freezing, ground contact | 3,000 psi |
| MW (moderate weathering) | Exterior above grade, mild climate | 2,500 psi |
| NW (negligible weathering) | Interior, back-up walls | 1,500 psi |
Always Use SW Grade Outside
In any climate with freezing weather, only use SW (severe weathering) grade brick for exterior walls, chimneys, pavements, and ground-contact applications. MW or NW will spall and crack after a few freeze cycles.Waste Factor and Ordering
- Straight walls no openings - 5 percent waste
- Walls with windows and doors - 10 percent
- Corners, soldier courses, curves - 15 percent
- Herringbone or complex patterns - 20 percent
Order From the Same Lot
Brick color varies noticeably between production runs. Always order all bricks at one time, from the same manufacturer and preferably the same kiln run. Buying extras later often produces a visible mismatch, especially in sun-exposed walls.