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Masonry + Plaster + Paint Estimator — PRO · International Standards Mode
📘 How it works
Take-off: net wall area (L×H − openings) × thickness → wall volume. Unit counts use actual unit size + joint (J) on length & height to form nominal (thickness unchanged). Mortar volume ≈ wall volume × (1 − actual/nominal). Plaster volume uses plaster thickness × plaster sides; paint litres use area ÷ coverage × coats. Labour can be computed either from crew productivity + day rates or direct per-m² if provided. Overheads/contingency/profit and GST/VAT are applied to subtotal.
Spec checks are advisory and do not replace project specs/codes.
Masonry + Plaster + Paint Estimator — PRO (International)
This article explains what the calculator does, the math behind it, how to use it, and includes a complete worked example with a jargon buster.
India (IS 2250 / IS 1661), United States (ASTM C270/C926 · TMS 402/602), UK/EU (BS EN 998-2 / EN 13914), Middle East (BS/EN or ASTM/TMS based).
Locks mortar options (e.g., Type N, M5, 1:4) and clamps typical ranges (joints, plaster thickness) per region.
1) What the calculator does
The PRO estimator performs a take-off and quick cost & labour sketch for masonry walls, plaster and paint. It supports Brick, CMU and AAC units and converts wall dimensions, openings, joints and thickness into:
- Wall volume (m³), unit counts (bricks/blocks)
- Mortar volume (m³) from the geometry of joints
- Plaster volume (m³) and paint/primer litres
- Cement & sand split by selected mix (e.g., 1:4, Type N, M5)
- Material, labour, overheads, tax and total
It also offers advisory spec checks that flag unusual inputs for the chosen region (e.g., joint thickness outside a typical band).
2) How it works (the math)
Geometry
- Net Wall Area = Length × Height − Openings
- Wall Volume = Net Area × Wall Thickness (thickness in metres)
- Nominal Unit uses actual unit size with the joint (J) added to Length & Height only; thickness is not inflated:
Vnominal = (L + J) × (H + J) × W
- Unit Count = Wall Volume × (1 + Waste) ÷ Vnominal (rounded up)
- Mortar Volume ≈ Wall Volume × (1 − Vactual / Vnominal)
- Plaster Volume = Net Area × Plaster Sides × Plaster Thickness
- Paint/Primer Litres = Area ÷ Coverage × Coats
Mix → Materials
For a volumetric mix like 1:4 (cement : sand), cement fraction is 1/(1+4)=0.2.
- Cement Volume = (Mortar × cement-fraction) + (Plaster × cement-fraction)
- Sand Volume = remainder (plus lime if present)
- Cement Bags (50 kg) use ~1440 kg/m³ loose density:
Bags ≈ ⌈ CementVol × 1440 ÷ 50 ⌉
Cost & Labour
- Material Cost = units & volumes × rates
- Labour via either per-m² rate or crew method:
Days = Area ÷ Productivity • Cost = Days × Crew × Day-Rate
- Apply Contingency, Overhead, Profit, then Tax
Advisory only — always confirm with project specs, local codes, and supplier data.
3) How to use the calculator
- Select Region (India / US / UK-EU / Middle East). Leave Standards Mode on to lock appropriate mortar menus and typical ranges.
- Add walls. For each row: Zone/Room, Unit Type & Preset, Length, Height, Thickness, Joint (J), Openings, Plaster Sides, Paint Sides, and Waste%.
- Choose mixes:
- Mortar: IS ratios (1:4) / ASTM types (Type N) / EN classes (M5) depending on region.
- Plaster: typical 1:4, 1:5 or 1:6; set thickness (e.g., 12 mm).
- Paint & Primer: enter coverage (m²/L/coat) and coats.
- Scenario A/B: Enter material rates, labour (crew or per-m²), and mark-ups. You can duplicate Scenario A → B to compare.
- Click 📊 Calculate & Review. KPIs update. Use 📝 Branded Report for print/PDF, or ⬇️ CSV.
4) Worked example — full project (International PRO)
Region: India • Mortar: 1:4 • Plaster: 1:4 @ 12 mm • Joint J: 10 mm • Waste: 5% • Paint: Primer 8 m²/L (1 coat), Paint 10 m²/L (2 coats)
Walls
| Wall | Unit (actual) | L × H (m) | Thk | J | Open | Plas | Paint |
|---|---|---|---|---|---|---|---|
| A | Brick Modular 190×90×90 mm | 5.0 × 3.0 | 100 mm | 10 mm | 0 m² | Both | Both |
| B | AAC 600×200×200 mm | 4.0 × 3.0 | 200 mm | 10 mm | 2 m² | Both | Both |
Step-by-step calculations
Wall A (Brick)
- Net area = 5 × 3 − 0 = 15.00 m²
- Wall volume = 15 × 0.10 = 1.50 m³
- Unit volumes
- Actual V = 0.19 × 0.09 × 0.09 = 0.001539 m³
- Nominal V (J on L & H) = (0.19+0.01) × (0.09+0.01) × 0.09 = 0.20 × 0.10 × 0.09 = 0.001800 m³
- Units = 1.50 × 1.05 ÷ 0.001800 = 875 bricks (ceiling)
- Mortar volume = 1.50 × (1 − 0.001539/0.001800) = 1.50 × 0.145 = 0.2175 m³
- Plaster volume = 15 × 2 × 0.012 = 0.36 m³
- Paint/Primer: area 15 × 2 = 30 m² → Primer 30/8 = 3.75 L; Paint 30/10 × 2 = 6.00 L
Wall B (AAC)
- Net area = 4 × 3 − 2 = 10.00 m²
- Wall volume = 10 × 0.20 = 2.00 m³
- Unit volumes
- Actual V = 0.60 × 0.20 × 0.20 = 0.024000 m³
- Nominal V (J on L & H) = (0.60+0.01) × (0.20+0.01) × 0.20 = 0.61 × 0.21 × 0.20 = 0.025620 m³
- Units = 2.00 × 1.05 ÷ 0.025620 = 81.96 → 82 blocks (ceiling)
- Mortar volume = 2.00 × (1 − 0.024/0.02562) ≈ 0.1265 m³
- Plaster volume = 10 × 2 × 0.012 = 0.24 m³
- Paint/Primer: area 10 × 2 = 20 m² → Primer 20/8 = 2.50 L; Paint 20/10 × 2 = 4.00 L
Totals
Mix → Materials
- Mortar 1:4 → cement fraction 0.2; Plaster 1:4 → cement fraction 0.2
- Cement volume = 0.34396×0.2 + 0.600×0.2 = 0.18879 m³
- Cement mass ≈ 0.18879 × 1440 = 271.85 kg → 6 bags (50 kg, rounded up)
- Sand volume (no lime) = 0.34396×0.8 + 0.600×0.8 = 0.755 m³
Costs (Scenario A – sample rates)
| Item | Qty | Rate | Amount (₹) |
|---|---|---|---|
| Bricks | 875 | ₹8 / brick | 7,000.00 |
| Blocks | 82 | ₹50 / block | 4,100.00 |
| Mortar | 0.34396 m³ | ₹3,500 / m³ | 1,203.86 |
| Plaster | 0.600 m³ | ₹3,800 / m³ | 2,280.00 |
| Primer | 6.25 L | ₹180 / L | 1,125.00 |
| Paint | 10.00 L | ₹250 / L | 2,500.00 |
| Materials subtotal | ₹18,208.86 | ||
Labour (crew method)
- Areas: Masonry 25 m²; Plaster 50 m²; Paint 50 m²
- Productivity: 25 / 35 / 250 m² per crew·day → Days: 1.00, 1.43, 0.20 → 2.63 days
- Crew cost: 4 workers × ₹900/day = ₹3,600/day → ₹9,462.85
Totals & mark-ups
| Subtotal (materials + labour) | ₹27,671.71 |
| Contingency @ 5% | ₹1,383.59 |
| Overhead @ 7% | ₹1,937.02 |
| Profit @ 10% (on subtotal + cont + OH) | ₹3,099.23 |
| Before tax | ₹34,091.55 |
| Tax @ 18% | ₹6,136.48 |
| Grand Total | ₹40,228.03 |
✔ Matches the calculator’s International PRO logic (J added to L & H only; thickness unchanged).
5) Jargon buster
- Actual vs Nominal unit
- Actual is the physical block/brick size. Nominal is the layout size allowing for joints; here, the joint is added to length and height only.
- Joint (J)
- Mortar thickness between units. Typical bands vary by region (e.g., IN ~6–12 mm; US ~9–13 mm). AAC thin-bed is often smaller but may be clamped by standards mode.
- Net area
- Gross wall area minus openings (doors/windows).
- Plaster sides
- How many faces get plaster (1 = one side, 2 = both sides).
- Mix ratio
- Proportion by loose volume. Example 1:4 = 1 part cement, 4 parts sand. ASTM/EN styles map to equivalent ratios (e.g., Type N ≈ 1:1:6, M5 ≈ 1:1:6).
- Coverage
- Paint/primer spread rate in m² per litre per coat.
- Scenario A/B
- Two sets of rates/productivity to compare pricing options.
6) Tips & notes
- Use the Region picker first; it adjusts mortar menus and clamps typical ranges.
- For AAC thin-bed adhesives, if your spec allows very low J, you can turn off Standards Mode to enter it explicitly.
- Waste% applies to unit counts; mortar volume already reflects joint geometry.
- Material densities and coverages are assumptions — replace with supplier-specific data for estimates you intend to submit.
- Reports and CSV exports are available after you calculate.
This tool supports estimating and planning. It is not a structural design check.
