🧱 Cement Sand Ratio Calculator
Professional mortar and concrete mix designer for plastering, brickwork, and flooring
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Project Details
Cement : Sand Ratio
💰 Cost Parameters
Material Requirements
Area
100
sq ft
Cement Bags
2.5
50kg bags
Sand Required
0.45
tons
Total Cost
$315
USD
📋 Calculation Breakdown
Wet Volume:
4.17 ft³
Dry Volume (×1.54):
6.42 ft³
Mix Ratio (C:S):
1:4
Cement Volume:
1.28 ft³
Sand Volume:
5.14 ft³
Water Required:
8.2 gal
Material Cost:
$225
Labor Cost:
$250
Total Project Cost:
$475
📊 Mix Reference Table (per 100 sq ft)
| Ratio | Thickness | Cement Bags | Sand (tons) | Application |
|---|---|---|---|---|
| 1:3 | ½" | 3.2 | 0.32 | Waterproofing |
| 1:4 | ½" | 2.5 | 0.33 | External plaster |
| 1:5 | ½" | 2.1 | 0.35 | Internal plaster |
| 1:6 | ½" | 1.8 | 0.36 | Light duty |
📊 Cement Sand Ratio Guide
| Ratio (C:S) | Application | Strength | Cost | Typical Use |
|---|---|---|---|---|
| 1:2 | Waterproofing | Very High | High | Water tanks, wet areas |
| 1:3 | Rich Mix | High | High | External plaster, high strength |
| 1:4 | Standard | Good | Moderate | External plaster, load-bearing walls |
| 1:5 | Economy | Fair | Low-Moderate | Internal plaster, non-load walls |
| 1:6 | Light Duty | Low | Low | Backing coat, temporary work |
| 1:8 | Very Light | Very Low | Very Low | Lime mortar, filling |
Frequently Asked Questions
What is the best cement sand ratio for plastering?
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 applications.
What is the standard cement sand ratio for brickwork?
For brick masonry, the standard ratio is 1:4 to 1:6 (cement:sand). For load-bearing walls, use 1:4. For partition walls, 1:5 or 1:6 is acceptable. The mortar should be workable with good bonding properties.
How do you calculate cement and sand for plastering?
Calculate plaster volume = Area × Thickness. Dry volume = Wet volume × 1.54. Cement = (Dry volume × Ratio) ÷ Total parts. Sand = (Dry volume × Sand ratio) ÷ Total parts. Example: 100 sq ft at 1/2 inch = 0.42 ft³ wet, 0.65 ft³ dry. For 1:4, cement = 0.65 ÷ 5 = 0.13 ft³ (1.3 bags).
What is the difference between 1:3, 1:4, and 1:6 mortar?
1:3 is a rich mix used for waterproofing and high-strength applications. 1:4 is standard for external plaster and load-bearing walls. 1:6 is an economical mix for internal plaster and non-load-bearing walls. Higher cement content gives more strength but costs more.
How many bags of cement per cubic foot of sand?
One 50kg bag of cement (1.25 ft³) requires: For 1:3 mix: 3.75 ft³ sand, For 1:4 mix: 5 ft³ sand, For 1:5 mix: 6.25 ft³ sand, For 1:6 mix: 7.5 ft³ sand. Coverage varies with mix ratio and application thickness.
What is the dry volume factor for mortar?
The dry volume factor is 1.54 (54% increase) to account for bulking of sand and shrinkage. Wet mortar volume × 1.54 = Dry mortar volume. This compensates for voids and ensures you order enough materials.