How this is calculated
Bricks per row is the wall length divided by brick length plus one mortar joint. Rows are wall height divided by brick height plus joint. Multiply and add waste for cuts at ends and openings.
Mortar is highly variable — mix design, joint width, and porous brick all change it. The mortar line is a planning figure based on roughly one bag per 120 bricks for standard work.
Formula & methodology
Bricks per row = floor(Length ÷ (brick + joint)). Rows = ceil(Height ÷ (brick + joint)). Total = rows × bricks per row × (1 + waste %).
Worked example
A 20 ft × 8 ft wall, standard US modular brick
- 1.Brick + joint ≈ 8 in ÷ 12 + 3/8 in ÷ 12 ≈ 0.70 ft per brick horizontally
- 2.Bricks per row ≈ 20 ÷ 0.70 ≈ 28
- 3.Rows ≈ 8 ÷ (2.25 in + joint) ≈ 42
- 4.Raw count ≈ 1,176 bricks; add 5% waste → ~1,235 bricks
Frequently asked questions
What brick size should I enter?
Use the nominal size printed on the spec sheet. US modular is often 8 × 2.25 in; UK standard is 215 × 65 mm plus a 10 mm joint.
Does this work for veneer?
Yes for a single wythe or veneer layer. Cavity walls and structural block cores need a separate count for the inner leaf.
How accurate is the mortar estimate?
It is a rough order-of-magnitude for pre-mixed mortar bags. Site-mixed lime mortar or wide joints will differ.
What about windows and doors?
This assumes a solid rectangle. Subtract openings manually or reduce the wall length/height to net dimensions before calculating.
Why add waste?
Cuts at corners, damaged bricks on delivery, and mismatched colour lots all eat into a tight count. 5% is a minimum; 10% is safer on small walls.
Single wythe vs double?
Run the calculator once per leaf if both sides are brick. A brick-on-block wall only needs a count for the outer brick layer.
Last updated 2026-09-01. Formulas are planning methods — confirm with a supplier before you order.