Brick and block calculator

This brick calculator answers "how many bricks do I need" for a single wall or a whole project. It takes the gross wall area, subtracts doors and windows, and multiplies the net area by the units per square foot of the brick or block you pick. It also works as a block calculator and cinder block calculator: choose a 4, 6, 8 or 12 in CMU (concrete masonry unit) and it switches to 16 × 8 in modules.

Alongside the count you get:

• mortar volume for the joints, so it doubles as a mortar calculator,
• the number of courses and a suggested lintel length over each opening,
• a wall elevation drawing showing the bond pattern,
• a materials list with editable unit prices and an estimated total, plus a free PDF and Excel export.

The tool starts in US units (ft, in, lb, cu ft) and switches to metric with one click. No sign-up, and everything is calculated in your browser.

The count comes from the face size of the unit plus the mortar joint: units per sq ft = 144 ÷ ((unit length + head joint) × (unit height + bed joint)), with dimensions in inches. US masonry is modular, so the nominal size already includes a 3/8 in joint.

*Before the waste allowance. Brick figures assume a single wythe with full mortar joints. CMU figures assume face-shell bedding: mortar only under the two face shells and in the head joints, not across the webs. All values can be overridden.

Example 1: brick veneer wall. A 20 ft long, 8 ft high wall in modular brick with one 3 × 4 ft window. Brick waste 5%, mortar waste 10%.

1. Gross area: 20 × 8 = 160 sq ft
2. Opening: 3 × 4 = 12 sq ft
3. Net area: 160 − 12 = 148 sq ft (13.75 m²)
4. Bricks: 148 × 6.75 × 1.05 = 1,048.95 → 1,049 bricks
5. Mortar: wall volume minus brick volume ≈ 5.9 cu ft per 100 sq ft → 148 sq ft × 1.10 ≈ 9.6 cu ft (about 273 L)

The wall is 36 courses high (three courses per 8 in). Divide the mortar volume by the yield printed on your mortar bag to get the number of bags.

Example 2: block wall. A 40 ft × 8 ft wall in 8 in CMU, no openings: 320 sq ft × 1.125 × 1.05 = 378 blocks in 12 courses, and about 5.1 cu ft of mortar with face-shell bedding and 10% waste.

• Type N is the common general-purpose mortar for above-grade veneer and non-load-bearing walls.
• Type S is stronger and is typically used below grade, for foundations, retaining walls and load-bearing block. Follow your plans and local code.
• Waste allowance: mortar gets dropped, stiffens in the tub and fills cores and voids, so 10% or more on top of the geometric volume is normal. If you lay hollow units in full bed joints instead of face-shell bedding, mortar drops into the cores; raise the mortar value or the allowance.
• Thin-bed mortar: precision units with ground faces, such as autoclaved aerated concrete blocks, are laid on a joint of only a few millimeters. There the tool works from the manufacturer's consumption per area instead of joint geometry, and it is far less material.

Grout for filled block cores is not part of the mortar figure. Work it out as concrete volume with the concrete calculator.

• Ordering the exact count. Cuts at corners and openings, chipped units and breakage add up. Plan on 5% for simple walls and more for many corners or patterns.
• Mixing nominal and actual sizes. An "8 × 8 × 16" block is really 7-5/8 × 7-5/8 × 15-5/8 in; the joint makes up the difference.
• Forgetting double wythes. A solid two-wythe brick wall needs twice the bricks of a veneer; calculate each wythe.
• Skipping lintels. Every opening needs one, longer than the opening by the bearing length at each end; the drawing shows where they go.
• Treating the estimate as engineering. For load-bearing or retaining walls, the engineer's drawings and local code come first.

Below the result you get a materials list: units, mortar and lintels, each with a default unit price based on rough 2026 big-box averages. Type in your own supplier prices; your browser remembers them and the estimated total updates instantly. Export the whole calculation, including the assumptions, to PDF or Excel for free, with no watermark and no account.

Next steps: the stucco calculator for the finish coats and the paint calculator for interior walls.