Free Masonry Calculator — Brick, Block & Paver Count

How to Use the Masonry Calculator

How to Calculate Masonry Materials

The number of masonry units per square foot is calculated with the formula Units/ft² = 144 ÷ ((Unit Length + Joint Width) × (Unit Height + Joint Width)). For standard modular bricks measuring 7-5/8" long × 2-1/4" high with a 3/8" mortar joint, the math works out to 144 ÷ ((7.625 + 0.375) × (2.25 + 0.375)) = 144 ÷ (8 × 2.625) = 6.86 bricks per square foot. To find the total number of bricks for a wall, multiply the net wall area (gross area minus openings) by 6.86, then add your waste factor. A 200-square-foot wall with 10% waste requires 200 × 6.86 × 1.10 = 1,509 bricks. Enter your wall dimensions into this masonry calculator and it handles the unit count, mortar estimation, and waste factor automatically.

This calculator supports bricks, CMU blocks, pavers, and tiles. Select your masonry unit type, enter the wall or paving area, subtract any door and window openings, and the calculator returns the total unit count, mortar bag estimate, and adjusted totals with your chosen waste percentage applied. All dimensions can be entered in feet-inches-fractions, decimal feet, decimal inches, or metric.

Understanding Masonry Unit Types

Masonry units come in a wide range of sizes, and the distinction between nominal and actual dimensions is critical for accurate material estimation. Nominal dimensions include the mortar joint — so a “standard modular” brick with a nominal size of 8" × 2-2/3" actually measures 7-5/8" × 2-1/4", with the 3/8" mortar joint making up the difference.

• Standard Modular Brick: 7-5/8" × 2-1/4" × 3-5/8" (L × H × D). The most common brick in residential construction — approximately 6.86 units per square foot with 3/8" joints. Three courses of modular brick plus three mortar joints equal exactly 8 inches, simplifying layout at window and door openings.
• King Size Brick: 9-5/8" × 2-3/4" × 2-3/4". A larger format that covers more area per unit — approximately 4.60 units per square foot. Popular in the southern United States for residential veneer.
• CMU Block (8×8×16): Actual dimensions 7-5/8" × 7-5/8" × 15-5/8". The standard concrete masonry unit requires approximately 1.125 blocks per square foot with 3/8" mortar joints. Used for foundations, retaining walls, and structural walls.
• Pavers and Tiles: Sizes vary widely — 4×8, 6×6, 12×12, and many custom formats. Pavers often use sand joints (1/16" to 1/8") rather than mortar joints, which significantly affects the units-per-square-foot calculation. Always confirm joint type before estimating.

Mortar Joint Width and Mortar Estimation

The standard mortar joint width is 3/8 inch for both brick and CMU block work, as specified by ASTM C270. Some decorative brickwork uses 1/2" joints for a more prominent joint line, while thin-set applications may use joints as narrow as 1/4". The joint width directly affects the number of units per square foot — wider joints mean fewer units are needed but more mortar is consumed.

For mortar estimation, the general rule is approximately 7 to 8 cubic feet of mortar per 1,000 standard bricks with 3/8" joints. That translates to roughly 15 bags of 60-lb Type S mortar mix or about 12 bags of 80-lb mix. For CMU blocks, plan on approximately 3 to 3.5 bags of 80-lb mortar per 100 blocks. These estimates include both bed joints (horizontal) and head joints (vertical) but not site waste — add 10–15% for spillage, tooling, and pointing.

Type S mortar (high strength, 1,800 psi) is specified for structural walls, below-grade applications, retaining walls, and areas subject to lateral loads or soil contact. Type N mortar (medium strength, 750 psi) is appropriate for above-grade, non-load-bearing walls, brick veneer, and interior partitions. When your local code or engineer does not specify a mortar type, use Type S — it costs marginally more but provides a significantly wider safety margin for structural performance.

Waste Factor for Masonry

Masonry waste comes from cutting units to fit around corners, openings, and ends of courses, as well as from breakage during handling and delivery. Choose your waste factor based on project complexity:

• 5% waste: Simple straight walls with few or no openings and a running bond pattern. Minimal cutting required — only end-of-course half bricks.
• 10% waste: Standard walls with doors and windows, inside/outside corners, and typical residential construction. This is the most common waste factor for brick and block projects.
• 15% waste: Complex patterns (herringbone, basket weave, Flemish bond), curved walls, numerous openings, or projects where color blending from multiple pallets is required. Also use 15% for inexperienced masons or projects with extensive soldier courses and rowlock sills.

Breakage during delivery typically runs 2–5% depending on handling conditions. Always inspect each pallet on arrival and document any damage before the delivery truck leaves. Running short mid-project is far more costly than having leftovers — a second delivery means additional freight charges and risks a color mismatch between brick lots.

Pro Tips

• Order 5–10% extra bricks from the same production lot for color consistency. Bricks from different kiln runs can vary noticeably in shade, and matching bricks months later for repairs or additions is often impossible.
• Mix mortar in small batches — mortar has a working time of only 30 to 45 minutes before it begins to set. Once mortar stiffens, do not re-temper it with water; discard it and mix a fresh batch to maintain bond strength.
• Keep bricks dry before laying. Contrary to popular belief, pre-wetting bricks weakens the mortar bond because excess surface water dilutes the cement paste at the brick-mortar interface. Only soak bricks if the manufacturer specifically recommends it for very high absorption units.
• Use story poles (course poles) — a straight board with course heights marked at regular intervals — to maintain consistent joint spacing from bottom to top. Check the story pole against the wall at every corner and at least every 4 feet along the face.
• Check level and plumb every 3–4 courses. Small errors compound rapidly in masonry — a 1/16" deviation per course becomes nearly 1" over a full-height wall. Use a 4' level on the wall face and a plumb bob or laser at corners.