Bricks are sold by the thousand and mortar by the eighty-pound bag, so the whole estimate is really two divisions. This calculator does both: bricks per square foot from real unit dimensions and joint width, then the mortar bags to match.
Quick answer: Modular brick with 3/8-in joints covers 6.857 bricks per square foot. An 8 × 3 ft wall (24 sq ft) needs 24 × 6.857 = 164.6 → 182 bricks with 10% waste, plus ~2 eighty-pound bags of mortar (9 bags per 1,000 bricks).
Ballpark, not gospel. The bag count is the standard estimating rule (~9 bags per 1,000 modular bricks at 3/8-in joints) — joints, waste, and brick size all move it. Mix a bag, lay a test section, and adjust before committing the full order.
| Brick size | Per sq ft |
|---|---|
| Modular (3⅝ × 2¼ × 7⅝ in) | 6.86 |
| Standard (3⅝ × 2¼ × 8 in) | 6.55 |
| Queen (2¾ × 2¾ × 7⅝ in) | 5.76 |
| King (2¾ × 2¾ × 9⅝ in) | 4.61 |
| Wall size | Bricks (10% waste) | Mortar bags (~) |
|---|---|---|
| 8 x 3 (garden bed) | 182 | 2 |
| 10 x 4 (garden wall) | 302 | 3 |
| 12 x 6 (privacy wall) | 544 | 5 |
Bag counts use 9 eighty-pound bags per 1,000 bricks, rounded up — mortar is always an ordering estimate, never a mix design.
Straight answers, no fluff. Then run your own numbers above.
For modular brick with 3/8-in joints: 144 / ((7.625 + 0.375) × (2.25 + 0.375)) = 144 / 21 = 6.857 bricks per sq ft, before waste. Standard is ~6.55, queen ~5.76, and king ~4.61 at the same joint width. Wider joints lower the count; narrower joints raise it.
The standard estimating rule is about 9 eighty-pound bags of mortar per 1,000 modular bricks with 3/8-in joints. An 8 × 3 ft garden wall needs ~182 bricks with waste (24 × 6.857 × 1.10), so ceil(0.182 × 9) = 2 bags. It scales with brick count, so other sizes price out proportionally.
3/8 inch is the US standard for brick — it forgives minor brick-size variation and is what the modular 6.857-per-sq-ft figure assumes. Use 1/4 in for crisp modern work with precise units, 1/2 in for rustic or tumbled brick. Every 1/8 in wider saves roughly 10% of your bricks but adds mortar.
No — it counts a single wythe, one brick thick, which covers brick veneer, garden walls, and fire-pit rings. For a double-wythe structural wall, run the calculator for one wythe and double the brick count. Mortar roughly doubles too, though the collar joint uses less than a full bed joint.
Yes — 10% is the default for straight walls and covers cuts, chipped units, and color blending (bricks vary slightly cube to cube; mixing them avoids patchy bands). Raise it to 15% for curved walls, soldier courses, or intricate patterns with heavy cutting.
Read how much mortar do I need for the full mortar breakdown, and for concrete masonry units — the CMU cousin of this calculator — see the concrete block calculator.