🧱 Plastering Materials Calculator
Estimate cement, sand, and water for wall and ceiling plaster
%
Wall/Ceiling Dimensions
Openings (Doors/Windows)
Mortar Mix Ratio
1:3 (Rich - Exterior)
1:4 (Standard Exterior)
1:5 (General Purpose)
1:6 (Internal - Economy)
💰 Cost Parameters
Plaster Material Results
Plaster Area
400
sq ft
Cement Required
12.5
bags (50kg)
Sand Required
1.2
tons
Total Cost
$525
materials + labor
📋 Material Breakdown
Net Plaster Volume:
16.7 ft³
Dry Volume (with 54% bulking):
25.7 ft³
Cement (50kg bags):
12.5 bags
Sand (tons):
1.2 tons
Water Required:
62 gallons
Material Cost:
$225
Labor Cost:
$300
📊 Material Summary
| Material | Quantity | Unit | Cost |
|---|---|---|---|
| Cement | 12.5 | 50kg bags | $150 |
| Sand | 1.2 | tons | $75 |
| Labor | 400 | sq ft | $300 |
📊 Plaster Mix Ratio Guide
| Mix Ratio (Cement:Sand) | Application | Thickness | Cement per 100 sq ft | Sand per 100 sq ft |
|---|---|---|---|---|
| 1:3 | Rich mix, exterior, waterproofing | ½" | 2.1 bags | 0.21 tons |
| 1:4 | Standard exterior, durable finish | ½" | 1.7 bags | 0.22 tons |
| 1:5 | General purpose, internal/external | ½" | 1.4 bags | 0.23 tons |
| 1:6 | Economy internal plaster | ½" | 1.2 bags | 0.24 tons |
| 1:2 (Lime) | Heritage/restoration work | ⅜" | 2.8 bags | 0.19 tons |
Frequently Asked Questions
How do you calculate plastering material?
Plaster volume = Area × Thickness. For 1:6 cement mortar, cement = (Volume × 1.54) ÷ 7, sand = (Volume × 1.54 × 6) ÷ 7. Add 20-25% for wastage and uneven surfaces. Water = 20-25% of cement weight.
What is the standard plaster thickness?
Internal walls: 12-15mm (½-⅝ inch). External walls: 15-20mm (⅝-¾ inch). Ceilings: 10-12mm (⅜-½ inch). Two-coat work: first coat 10-12mm, second coat 6-8mm. Thicker for uneven walls.
What is the best cement-sand ratio for plaster?
Internal plaster: 1:4 to 1:6 (cement:sand). External plaster: 1:3 to 1:4 (for durability). Ceiling plaster: 1:3 (to prevent sagging). Rough finish: 1:5. Fine finish: 1:4. Add waterproofing for exterior.
How much area does 1 bag of cement cover for plaster?
One 50kg bag of cement covers approximately: 30-35 sq ft at 12mm thickness with 1:6 ratio, 25-30 sq ft at 15mm thickness, 20-25 sq ft at 20mm thickness. Coverage varies with mix ratio and wastage.
How do you calculate plaster for a wall?
Measure wall length × height = area. Subtract door/window openings. Multiply area by thickness for volume. Add 20% for wastage. Use mix ratio to calculate cement and sand. Example: 100 sq ft at ½ inch = 0.42 cubic feet of plaster.
What is the curing time for plaster?
Plaster should be cured for 7-14 days. Initial set: 30 minutes. Final set: 24 hours. Keep moist for at least 7 days. Sprinkle water 3-4 times daily. Proper curing prevents cracks and ensures strength.