Brick Joint Calculator
Calculate equal mortar joint width for a course length and brick count. 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:
- One straight course with joints only between bricks. End joints and expansion joints are excluded.
- A geometric fit is not a recommendation to exceed the specified joint tolerance.
Advertisement — after results
Reserved for AdSense — no layout shift.
Brick Joint — Finished course length × Actual brick length · 3/8" joint
What Is This Calculator?
The Brick Joint 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
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
Joint width = (course length − brick count × actual brick length) / (brick count − 1).
- 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
- One straight course with joints only between bricks. End joints and expansion joints are excluded.
- A geometric fit is not a recommendation to exceed the specified joint tolerance.
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.
Related calculators
Brick Calculator
Calculate brick — units per wall area with mortar joint, wei...
Brick Wall Calculator
Calculate brick wall — units per wall area with mortar joint...
Brick Quantity Calculator
Calculate bricks needed per wall area — account for brick si...
Brick Cost Calculator
Estimate brick cost — material, quantity and price with wast...
Brick Mortar Calculator
Calculate brick mortar — units per wall area with mortar joi...
Brick Veneer Calculator
Calculate brick veneer — units per wall area with mortar joi...
Frequently asked questions
What does the Brick Joint Calculator calculate?
The Brick Joint Calculator estimates brick joint 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 brick joint?
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 brick joint 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.