Cement Calculator

Professional cement calculator for accurate estimation of cement, sand, and aggregate quantities for concrete and mortar projects

Concrete
Mortar
Construction

Cement Calculator

Mix Type

Volume Parameters

Default Ratios:
• Concrete: 1.54:1
• Mortar: 1.22:1
• Cement & Water: 1:1

Concrete Mix Ratio

Ratio of cement to sand to gravel with estimated compressive strength

Cement Properties

Select mix type and enter parameters, then click Calculate

Understanding Cement Calculations

Cement is the binding material in concrete and mortar. Accurate cement calculation ensures structural integrity, prevents material waste, and optimizes project costs. This calculator helps you determine the exact amount of cement needed based on your project requirements.

The calculation accounts for the dry-to-wet volume ratio, which represents how dry materials expand when mixed with water. Different mixtures have different ratios:

Standard Dry-to-Wet Ratios:
  • Concrete: 1.54:1 (dry materials increase by 54% when wet)
  • Mortar: 1.22:1 (dry materials increase by 22% when wet)
  • Cement & Water: 1:1 (no volume change)

How to Calculate Cement Quantity?

Calculating cement quantity involves several steps to ensure accuracy and account for material properties.

Calculation Steps

1
Calculate Dry Volume
Dry Volume = Wet Volume × Dry-to-Wet Ratio

Example: 1 m³ wet volume × 1.54 = 1.54 m³ dry volume

2
Add Waste Factor
Total Volume(Dry) = Dry Volume × (1 + Waste%/100)

Example: 1.54 m³ dry volume × (1 + 10/100) = 1.694 m³

3
Apply Mix Ratio
Cement Volume = Total Dry Volume × (Cement Parts / Total Parts)

Example: For 1:1.5:3 mix, Cement = 1.694 × (1/5.5) = 0.308 m³

4
Calculate Weight and Bags
Weight = Volume × Density
Bags = Weight / Bag Size

Example: 0.308 m³ × 1440 kg/m³ = 443.5 kg ≈ 9 bags (50kg each)

Common Mix Ratios

Concrete Mix Ratios

1:5:105.0 MPa (725 psi) - Low strength
1:3:610.0 MPa (1450 psi) - General use
1:1.5:320.0 MPa (2900 psi) - Standard strength
1:1:225.0 MPa (3625 psi) - High strength

Mortar Mix Ratios

1:6Interior plaster
1:5Brickwork mortar
1:4Exterior plaster
1:3Rich mortar mix

Practical Calculation Example

Let's calculate cement requirements for a concrete slab project.

Example: Concrete Slab Foundation

Project Specifications:
  • Mix Type: Concrete
  • Wet Volume: 10 cubic meters (m³)
  • Dry-to-Wet Ratio: 1.54:1
  • Waste Factor: 10%
  • Mix Ratio: 1:1.5:3 (20.0 MPa)
  • Cement Density: 1440 kg/m³
  • Bag Size: 50 kg

Step-by-Step Calculation

1. Calculate Total Dry Volume
Total Dry Volume = 10 m³ × 1.54
Total Dry Volume = 15.4 m³
2. Calculate Total Volume(Dry) with Waste
Total Volume(Dry) = 15.4 m³ × (1 + 10/100)
Total Volume(Dry) = 16.94 m³
3. Calculate Cement Volume (1:1.5:3 ratio)
Total Parts = 1 + 1.5 + 3 = 5.5
Cement Volume = 16.94 m³ × (1/5.5)
Cement Volume = 3.08 m³
4. Calculate Cement Weight
Cement Weight = 3.08 m³ × 1440 kg/m³
Cement Weight = 4435.2 kg
5. Calculate Bags Needed
Bags = 4435.2 kg ÷ 50 kg/bag
Bags = 89 bags (rounded up)
6. Other Materials
Sand Volume = 16.94 m³ × (1.5/5.5) = 4.62 m³
Gravel Volume = 16.94 m³ × (3/5.5) = 9.24 m³
Water Weight = 4335.2 kg × 0.4 (default Water–Cement ratio) = 1784.08 kg
Final Requirements:
  • • Cement: 3.08 m³ (4435 kg, 89 bags)
  • • Sand: 4.62 m³
  • • Gravel: 9.24 m³

Why Use Our Cement Calculator?

Accurate Calculations – Industry-standard formulas with dry-to-wet ratios
Multiple Mix Types – Support for concrete, mortar, and cement-water mixes
Complete Material Breakdown – Calculate cement, sand, gravel, and water quantities
Flexible Units – Support for metric and imperial volume units
Waste Accounting – Include waste factors for realistic estimates

Calculator Features

Multiple Units

Calculate with cubic meters, feet, yards, liters, gallons, and more volume units.

Standard Mix Ratios

Pre-configured ratios for various strength grades and applications.

Instant Results

Real-time calculations with automatic updates as you adjust parameters.

Cement Calculator FAQ

For standard 1:1.5:3 concrete mix (20 MPa), you need approximately 6.3 bags of 50kg cement per cubic meter. The exact number depends on the mix ratio and waste factor. Higher strength mixes require more cement.

Wet volume is the final volume after mixing all materials with water. Dry volume is larger because dry materials have air gaps between particles that get filled when water is added. For concrete, dry volume is typically 1.54 times the wet volume.

Waste factor accounts for material spillage, uneven surfaces, over-excavation, and mixing losses. A 10% waste factor is standard for most projects. This ensures you have enough materials to complete the project without shortages.

Mix ratios depend on strength requirements: 1:5:10 for low-strength (5 MPa), 1:1.5:3 for standard strength (20 MPa), and 1:1:2 for high-strength (25 MPa). Consult structural plans or engineers for specific requirements.

Yes! Select 'Mortar' as the mix type and choose appropriate ratios: 1:6 for interior plaster, 1:5 for brickwork, 1:4 for exterior plaster, or 1:3 for rich mortar mix. The calculator automatically adjusts for mortar's different dry-to-wet ratio (1.22:1).

Calculate Cement for Your Project

Get accurate cement, sand, and aggregate calculations for your concrete or mortar project. Ensure proper mix ratios and avoid material shortages or excess.