🏗️ Concrete Volume Calculator
Calculate the exact quantity of concrete, cement bags, sand, and aggregate required for your construction project. Supports slabs, columns, and footings with multiple concrete mix ratios (M20, M15, M10, M7.5).
M20 Concrete
8 bags/m³
Cement required
M15 Concrete
6.3 bags/m³
General purpose
Cement Density
1440 kg/m³
50 kg per bag
Wastage Factor
5%
Recommended extra
Project Details
Total Volume
1.70
m³60.0 cu ft
Cement Bags
11
50kg bags
Material Required
Cement
544 kg
Sand
1,088 kg
Aggregate
2,176 kg
For M15 concrete (1:2:4 mix), includes 5% wastage
Quick Reference Guide
8 bags cement/m³
6.3 bags cement/m³
4.5 bags cement/m³
50 kg = 1.25 cu ft
How to Calculate Concrete Quantity?
For a rectangular slab: Volume = Length × Width × Thickness. For M15 concrete (1:2:4), cement quantity = (Volume × 1440 × 1) ÷ (1+2+4) kg. Dry volume factor of 1.54 is applied to convert wet concrete volume to dry materials volume.
Volume Formulas
- 🏠 Slab / Rectangle: L × W × T
- ⭕ Column / Circle: π × r² × H
- 📐 Footing / Trapezoid: (A₁ + A₂) ÷ 2 × H × L
Mix Ratios (Cement:Sand:Aggregate)
- M20 (High Strength): 1 : 1.5 : 3 - For RCC slabs, beams, columns
- M15 (General): 1 : 2 : 4 - For general RCC work
- M10 (PCC): 1 : 3 : 6 - For plain cement concrete, foundations
- M7.5 (Lean): 1 : 4 : 8 - For mass concrete, foundations
📐 Sample Calculation (10' × 12' × 6" Slab)
Volume (wet) = 10 × 12 × (6/12) = 60 cu ft = 1.70 m³
Dry volume = 1.70 × 1.54 = 2.62 m³
For M15 (1:2:4): Cement = 2.62 × 1440 × (1/7) = 544 kg = 11 bags
Sand = 2.62 × 1600 × (2/7) = 1,198 kg | Aggregate = 2.62 × 1500 × (4/7) = 2,245 kg
❓ Frequently Asked Questions
How many cement bags per cubic meter of concrete?
For different concrete grades:
• M20: Approximately 8 bags (400 kg) per m³
• M15: Approximately 6.3 bags (315 kg) per m³
• M10: Approximately 4.5 bags (225 kg) per m³
• M7.5: Approximately 3.5 bags (175 kg) per m³
What is the dry volume factor 1.54?
When dry materials (cement, sand, aggregate) are mixed with water, they occupy less volume due to chemical reaction and air voids. Wet concrete volume is approximately 54% less than dry volume. Therefore, dry volume = wet volume × 1.54.
Should I order extra concrete?
Yes, always order 5-10% extra concrete for wastage due to uneven subgrade, spillage during pouring, and formwork variations. Our calculator automatically adds 5% wastage.
What is the difference between M15, M20, M25 concrete?
'M' stands for Mix, and the number indicates characteristic compressive strength in N/mm² after 28 days.
• M10: 10 N/mm² - For PCC, footings
• M15: 15 N/mm² - For general RCC work
• M20: 20 N/mm² - For structural RCC, slabs, beams
• M25: 25 N/mm² - For high-rise buildings, bridges
What is the density of cement, sand, and aggregate?
• Cement: 1440 kg/m³ (1 bag = 50 kg = 1.25 cu ft)
• Sand: 1600 kg/m³ (loose state)
• Coarse Aggregate: 1500 kg/m³
• Water: 1000 kg/m³