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Concrete Volume Calculator

Calculate concrete volume for slabs, columns, footings, walls, and cylinders. Get instant material quantities including cement bags, sand, and aggregate with waste factor.

Concrete Engineering Engineers, contractors, students, DIY builders Commercial Intent: HIGH

Shape Visualization

Mix Proportions

Engineering Formulas

Net Volume (Rectangular)

V = L × B × D

V: Volume

L: Length

B: Width

D: Depth/Thickness

Net Volume (Circular)

V = π × (Ø/2)² × H

V: Volume

Ø: Diameter

H: Height

Volume with Waste

V_total = V × (1 + W/100)

V_total: Total volume with waste

V: Net volume

W: Waste factor (%)

Material Breakdown

Cement = (1/Σratio) × Vdry × 1440 / 50
Sand = (sandratio/Σratio) × Vdry
Aggregate = (aggratio/Σratio) × Vdry

V_dry: Dry volume (× 1.54)

Σ_ratio: Sum of mix ratios

Worked Example

Ground Floor Slab — 6m × 4m Room

shape: slablength: 6width: 4depth: 0.15quantity: 1wasteFactor: 5concreteGrade: M20

Net Volume

6 × 4 × 0.15 = 3.600 m³

Volume with Waste

3.600 × 1.05 = 3.780 m³

Dry Volume

3.780 × 1.54 = 5.821 m³

M20 Mix Ratio

1 : 1.5 : 3, Sum = 5.5

Cement Required

(1/5.5) × 5.821 × 1440 / 50 = 30.5 → 31 bags

Sand Required

(1.5/5.5) × 5.821 = 1.588 m³

Aggregate Required

(3/5.5) × 5.821 = 3.176 m³

Result: For a 6m × 4m × 0.15m slab, you need approximately 31 bags of cement, 1.59 m³ of sand, and 3.18 m³ of aggregate for M20 grade concrete with 5% waste.

Engineering Notes

For structural elements, always consult IS 456, ACI 318, or BS 8110 for minimum grade requirements.

This calculator gives material quantities for procurement; structural design must be performed separately.

Ready-mix orders should add 10% for forms, spills, and uncertainty.

For mass concrete (thick foundations), consider thermal cracking risk and use lower heat cement.

Assumptions

• Concrete density: 2,400 kg/m³ (normal weight concrete)

• Dry volume factor: 1.54 (industry standard for cement/sand/aggregate breakdown)

• Cement bag weight: 50 kg

• Mix ratio based on selected grade; nominal mix per IS 456 / ACI 211

• No reinforcement volume deducted (conservative for material ordering)

Common Mistakes

✕ Forgetting to include waste factor — always add 5–10%

✕ Using wet volume for material calculations instead of dry volume × 1.54

✕ Calculating only one panel when there are multiple identical elements

✕ Using wrong concrete grade for structural vs non-structural applications

✕ Ignoring reinforcement when estimating total concrete weight

Frequently Asked Questions

What is the standard waste factor for concrete?

For site-mixed concrete, allow 5–10% waste. For ready-mix concrete, 3–5% is typical due to precise batching. The default in our calculator is 5%.

What is the dry volume factor of 1.54?

When concrete is mixed, the dry ingredients (cement, sand, aggregate) have voids between particles. The wet concrete volume is approximately 1.54 times the dry volume. This accounts for bulking of sand, voids in aggregate, and general compaction during mixing.

How many bags of cement per cubic metre?

For M20 grade (1:1.5:3), approximately 8 bags per m³ of wet concrete. For M15 (1:2:4), about 6.5 bags. For M25 (1:1:2), about 9.5 bags. Use our calculator for exact quantities based on your specific grade and waste factor.

What is the difference between M15, M20, M25?

The 'M' stands for 'Mix' and the number indicates characteristic compressive strength in MPa at 28 days. M15 = 15 MPa (non-structural), M20 = 20 MPa (general construction), M25 = 25 MPa (structural). Higher grades use more cement and less aggregate.

Can I use this for ready-mix concrete orders?

Yes. Add a 10% allowance for forms, spills, and pump losses on top of the calculated volume. Inform the ready-mix plant of your required grade (e.g., M20). Our calculator provides the volume; the plant handles the mix design.