About this calculator
This brick calculator estimates how many bricks and how much mortar a single-wythe wall needs — a garden wall, raised planter, veneer or chimney face. It uses the actual brick dimensions plus your mortar joint to find bricks per square foot, so it works for modular, standard, queen, king and utility sizes.
The drawing shows the wall to scale with every brick in half running bond, so you can see the courses and the pieces you’ll cut at the ends. Below it you get the number of courses and bricks per course, and the cost at your local prices. For a double-wythe (two-brick-thick) wall, double the results.
How to use it
- Enter the length and height of the wall face.
- Subtract the area of any openings such as doors, windows or vents, in square feet.
- Choose the brick size and mortar joint (⅜ in is standard).
- Keep 5% extra for broken bricks and cuts, or 10% for walls with many corners, and add your prices to see the cost. Check the drawing for the courses and the cut pieces at the ends.
The formula
Bricks per sq ft = 144 ÷ ((brick length + joint) × (brick height + joint))
Bricks = (wall area − openings) × bricks per sq ft × (1 + extra%)
Mortar bags ≈ bricks ÷ 37 (80 lb bags, modular brick)
Courses = wall height ÷ (brick height + joint), rounded
A modular brick with a ⅜ in joint occupies 8 × 2⅝ in of wall — 21 square inches — which gives 6.86 bricks per square foot. Mortar is estimated from the manufacturer’s figure of about 37 modular bricks per 80 lb bag of mortar mix and scaled for larger or smaller bricks by joint length.
Each course is one brick plus one bed joint: 2⅝ in for modular brick, which the Brick Industry Association lays out as 3 courses to 8 in. The mason makes the bed joints a touch thicker or thinner so the last course lands on the wall height.
Worked example
These are the calculator’s starting values and the results they produce:
| Wall length | 20 ft |
|---|---|
| Wall height | 4 ft |
| Area of openings to subtract | 0 sq ft |
| Brick size | Modular (7⅝ × 2¼ in) |
| Mortar joint | 0.375 in |
| Extra for breakage and cuts | 5 % |
| Brick, each | $0.75 |
| Mortar mix, per 80 lb bag | $10.00 |
Tips before you buy
- Buy all bricks for a project from the same production run; colors vary between batches.
- Mortar coverage depends on joint depth and how much drops — keep a spare bag on hand.
- Walls over about 3 ft tall, retaining walls and anything load-bearing need a proper footing and may need an engineer or permit.
- Type N mortar suits most above-grade garden and veneer walls; Type S is stronger and is used below grade and for structural work.
Frequently asked questions
How many bricks are in a square foot?
About 6.86 modular bricks per square foot with a ⅜ in mortar joint. Queen bricks work out to about 5.8 per square foot, king bricks about 4.8 and utility bricks 3.0.
How many bricks per bag of mortar?
Quikrete lists about 37 standard bricks per 80 lb bag of mortar mix. Larger bricks lay more wall area per bag because there are fewer joints.
How many bricks do I need for a 20 ft long, 4 ft high wall?
The wall is 80 square feet, so about 549 modular bricks, or 576 with 5% extra — and roughly 16 bags of 80 lb mortar mix. At $0.75 a brick and $10 a bag that’s about $592.
How many courses of brick are in a 4 ft wall?
18 courses of modular brick. Each course is a 2¼ in brick plus a ⅜ in joint, 2⅝ in, and the Brick Industry Association counts 3 modular courses to 8 in: 48 ÷ 8 × 3 = 18. A 20 ft wall takes about 30 bricks per course.
Sources
Areas and volumes are standard geometry. The published figures this calculator relies on come from these sources; other defaults (waste allowances, typical densities and prices) are common trade figures worth checking with your supplier.
- Brick Industry Association Technical Note 10: Dimensioning and Estimating Brick Masonry: brick sizes (modular, standard, queen, king, utility), estimating by wall area, 3 modular courses to 8 in and at least 5% extra brick
- Quikrete Mortar Mix data sheet 1102: an 80 lb bag of mortar mix lays about 37 modular bricks