Mortar Quantity Calculator estimates mortar volume and rate per area for brick/block masonry based on wall size, joint thickness, and wastage. Use it for quick take-offs, ordering, and cross-checking site consumption.
About wall area. Wall area can be entered directly or derived from wall length × wall height. Openings are typically subtracted in detailed take-offs, but for quick estimates an allowance can be left in the wastage factor.
About joint thickness. Joint thickness controls mortar demand. A common reference is 10 mm bed and head joints for modular brickwork; thicker joints increase volume approximately linearly. For imperial workflows, joint thickness is often specified in inches (e.g., 3/8 in).
About wastage. Wastage (%) accounts for cutting losses, spillage, uneven substrates, and workmanship variability. Typical allowances range from 5–15% depending on unit size and site practice.
About units. The tool supports metric and imperial. Inputs and results can be viewed in m²/ft² for area, mm/in for joints, and m³/yd³ for volume.
Conversion / Calculation. Mortar demand is modeled using a reference rate per unit area at a 10 mm joint, scaled linearly by the specified joint thickness and adjusted by the wastage factor. When wall area is not provided, it is computed from length and height.
Formulas:
- A = L × H (wall area from dimensions)
- r = r0 × (jt / 10 mm) (area rate scaled by joint thickness)
- V = A × r × (1 + w/100) (total mortar volume with wastage)
- R = V / A = r × (1 + w/100) (practical rate per area for ordering)
where: A = wall area; L = length; H = height; jt = joint thickness; w = wastage (%). The reference rate r0 = 0.012 m³/m² at jt = 10 mm.
Examples:
- Quick area estimate. A = 50 m², jt = 10 mm, w = 5%
r = 0.012 × (10/10) = 0.012 m³/m²
V = 50 × 0.012 × 1.05 = 0.630 m³ (≈ 0.825 yd³) - From dimensions. L = 12 m, H = 3 m ⇒ A = 36 m²; jt = 12 mm; w = 8%
r = 0.012 × (12/10) = 0.0144 m³/m²
V = 36 × 0.0144 × 1.08 = 0.560 m³ (≈ 0.733 yd³) - Imperial units. A = 600 ft², jt = 3/8 in, w = 7%
A ≈ 55.742 m²; jt = 9.525 mm; r = 0.012 × (9.525/10) = 0.01143 m³/m²
V = 55.742 × 0.01143 × 1.07 ≈ 0.682 m³ (≈ 0.892 yd³)
Corresponding tools.
Brick/Block Quantity Calculator,
Plaster/Render Quantity Calculator,
Concrete Volume Calculator,
Section Properties,
Beam Deflection Calculator.
