Masonry Block Calculator
Calculate masonry block — units per wall area with mortar joint, weight and cost with waste. Enter brick dimensions to get instant results. Enter dimensions, select units and add waste to get instant, supplier-ready numbers.
Enter dimensions above to calculate
- Enter values to see step-by-step substitution.
Engineering Assumptions:
- Use the exposed face dimensions, not the unit depth. Defaults describe one wythe of modular brick.
- A nominal 16 × 8 in CMU face includes its joints: enter actual dimensions 15⅝ × 7⅝ in with a ⅜ in joint.
- This is an area estimate. Corners, returns, lintels, bond patterns, caps and special units require a separate takeoff.
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Masonry Block — Wall length × Wall height · 3/8" joint
What Is This Calculator?
The Masonry Block Calculator — Counts bricks and masonry units for US walls, patios and veneers — quantity, mortar and cost.
What Does It Calculate?
- Bricks or blocks per wall area
- Mortar volume with 3/8 in joint
- Waste-adjusted count and cost
How to Use the Calculator
- Measure Wall 20 ft x 8 ft, brick 7.5x2.25 in, joint 0.375 in — use feet for length/width and inches for thickness where typical.
- Enter values and select units. The calculator converts to feet before calculating (inches /12, yards x3).
- Adjust waste % and optional price, then click Calculate. Results show with waste included.
- Use Reset to clear and try another size.
Formula & Engineering Methodology
Net wall area = length × height − openings; units = ceil(net area × allowance factor / ((unit length + joint) × (unit height + joint))).
- Wall area — Length x Height in ft2
- Brick area — (Brick L + joint) x (Brick H + joint)
All units convert to exact standard engineering dimensions (NIST SP 811) before calculation to ensure consistency between US Customary and Metric measurements.
Worked Example
Example: Wall 20 ft x 8 ft, brick 7.5x2.25 in, joint 0.375 in
| STEP | VALUE |
|---|---|
| Wall area | 160 ft2 = 23,040 in2 |
| Brick + joint | 7.875x2.625 = 20.67 in2 |
| Bricks | ceil(23,040/20.67)=1,115 |
| With 7% waste | 1,193 |
Construction Information
Material: Standard brick 7.5x2.25 in, 6.8 per ft2 with 3/8 in joint. Mortar Type S 1:3, Type N 1:4. CMU 16x8 in face (1.125 per ft2).
- Measure longest x widest; split L-shapes into two rectangles and add.
- Compact subgrade — soft spots add thickness.
- For structural sizing (beams, headers, rebar) verify with a professional per local code.
Material Information
Standard brick 7.5x2.25 in, 6.8 per ft2 with 3/8 in joint. Mortar Type S 1:3, Type N 1:4. CMU 16x8 in face (1.125 per ft2).
Waste & Overages
Add 7% for cuts and breakage — 10% for arches or curves.
Practical Tips
- Dry-lay a course to check bond
- Keep mortar workable — do not retemper after initial set
Common Mistakes
- Forgetting joint thickness — count off 15%
- Not adding waste for cuts around openings
Assumptions & Engineering References
- Use the exposed face dimensions, not the unit depth. Defaults describe one wythe of modular brick.
- A nominal 16 × 8 in CMU face includes its joints: enter actual dimensions 15⅝ × 7⅝ in with a ⅜ in joint.
- This is an area estimate. Corners, returns, lintels, bond patterns, caps and special units require a separate takeoff.
This calculator provides an estimate based on your inputs. Actual requirements vary by site, material and installation. For code-regulated or load-bearing work, consult a qualified professional.
Calculations run 100% in your browser — zero tracking of your dimensions or input data.
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Frequently asked questions
What does the Masonry Block Calculator calculate?
The Masonry Block Calculator estimates masonry block quantity for US jobs — Bricks or blocks per wall area, Mortar volume with 3/8 in joint, Waste-adjusted count and cost. Enter dimensions, choose units, add waste and price to get instant results.
How do I measure for masonry block?
Measure wall 20 ft x 8 ft, brick 7.5x2.25 in, joint 0.375 in on site. Use the unit selectors — the tool converts inches→feet (÷12) and yards→feet (×3) before math. For non-rectangular, split into rectangles and add.
How much waste should I add?
Add 7% for cuts and breakage — 10% for arches or curves.
How accurate is this masonry block estimate?
Math is exact for your inputs. Actual needs vary by site, material and installation. Add 5–10% waste for rectangular, 10–15% for irregular.
About Calculator Street
Built by Vipul Otari for US homeowners & contractors. Calculator inputs are processed in your browser. Estimates depend on your measurements, product specifications and the assumptions shown on this page. Confirm order quantities with your supplier and structural requirements with your project designer. Page updated: 2026-09-11.