Calculate exactly how much concrete you need for slabs, footings, walls, and columns. Instant results in cement bags, cubic yards, cubic feet, and cubic meters. Supports M10, M15, M20, M25, M30 grades and PSI 3000/4000 with full material breakdown, wastage factor, and cost estimate.
M20+ for structural. Consult engineer.
Includes spillage and material waste
Costs vary by location. Estimates only.
Get your concrete quantity in under 60 seconds — follow these steps:
Select Your Project Shape
Choose between a rectangular slab (for driveways, patios, footings) or a cylindrical column (for piers, sonotubes, fence posts).
Choose Your Unit System
Select Imperial (feet/inches) for US projects or Metric (meters/cm) for international projects. All conversions are handled automatically.
Enter Your Dimensions
For slabs: enter Length, Width, and Thickness. For columns: enter Diameter and Height. Convert inches to feet first — divide inches by 12 (e.g., 4 inches = 0.333 ft).
Add Price Per Cubic Meter (Optional)
Enter your local ready-mix concrete price per cubic meter for an instant project cost estimate. Skip this field if you only need volume.
Click Calculate
Results show instantly: volume in cubic feet, cubic yards, and cubic meters — plus exact cement bag count and cost estimate if price was entered.
Most online concrete calculators only give you cubic yards. Ours goes further — giving contractors and homeowners everything needed to actually order and pour concrete.
| Feature | VIP Calculator | calculator.net | omnicalculator | inchcalculator |
|---|---|---|---|---|
| Volume in ft³, yd³ and m³ | ✅ | ✅ | ✅ | ✅ |
| Cement bags estimation (50kg/80lb) | ✅ | ❌ | ✅ | ✅ |
| Sand & aggregate quantities | ✅ | ❌ | ❌ | ❌ |
| M10 / M15 / M20 / M25 mix ratios | ✅ | ❌ | ❌ | ❌ |
| Dry volume factor (1.54) explained | ✅ | ❌ | ❌ | ❌ |
| Water-cement ratio guidance | ✅ | ❌ | ❌ | ❌ |
| Temperature pour guidelines | ✅ | ❌ | ❌ | ❌ |
| Waste factor recommendation (10%) | ✅ | ❌ | ❌ | ✅ |
| Visual shape diagrams | ✅ | ❌ | ❌ | ❌ |
| Step-by-step worked examples | ✅ | ❌ | ✅ | ❌ |
| Unit conversion table | ✅ | ❌ | ❌ | ✅ |
| 100% browser-based (no data upload) | ✅ | ✅ | ✅ | ✅ |
Comparison based on publicly available features of competitor tools as of 2026.
✅Order Exactly What You Need
Avoid the two most expensive concrete mistakes: ordering too little (emergency delivery fees) or too much (disposal charges). Precise volume = no wasted money.
💵Save Money on Every Project
Even a 0.5 yd³ overcalculation on a driveway wastes $60–$100. This calculator pays for itself on the first use.
📊Accurate Project Budgets
Built-in cost estimator lets you compare ready-mix quotes against your budget before committing — critical for contractor bidding.
🌱Reduce Material Waste
Overordering concrete means excess material that must be washed out and disposed of — an environmental and cost burden. Calculate right the first time.
🔄Compare Scenarios Instantly
Should you pour 4-inch or 6-inch thickness? Adjust inputs and see the cost difference in seconds — without recalculating by hand.
👷Trusted by Pros & DIYers
Uses the same dry volume factor (1.54) and mix ratio standards (ACI 211.1) that professional estimating software uses — just faster and free.
US PSI to Metric MPa to Indian M-Grade — Complete Reference:
| M-Grade | Strength (MPa) | Strength (PSI) | Best For (US Context) |
|---|---|---|---|
| M10 | 10 MPa | 1,450 PSI | Lean concrete, blinding coat |
| M15 | 15 MPa | 2,175 PSI | Residential footings, light pavements |
| M20 | 20 MPa | 2,900 PSI | Driveways, patios, slabs, beams |
| M25 | 25 MPa | 3,625 PSI | Heavy-duty floors, columns, bridges |
| M30 | 30 MPa | 4,350 PSI | High-rise structures, water-retaining |
| — | — | 4,000 PSI | Standard US driveway (ACI 318 minimum) |
| — | — | 5,000 PSI | US commercial floors, garage slabs |
Reference: ACI 318-19 (American Concrete Institute) · IS 456:2000 (Indian Standard)
| Project Type | Add Extra | Reason |
|---|---|---|
| Flat slab / patio | 5–8% | Minimal spillage, easy to control pour |
| Driveway | 8–10% | Slight grade variation, edge forms |
| Foundation footing | 10–15% | Irregular trench walls absorb extra |
| Concrete column | 15–20% | Vertical form pressure causes more waste |
| Fence post holes | 20–25% | Cylindrical holes hard to fill precisely |
| Steps / stairs | 10–15% | Complex formwork with multiple faces |
| Retaining wall | 10–12% | Wall thickness variations and overlap |
Always round up to the nearest 0.25 yd³ when ordering ready-mix — suppliers charge for minimum loads regardless.
Expert Note:
Concrete quantity is calculated using a dry volume factor of 1.54, as dry materials (cement, sand, aggregate) occupy more space before water is added. After mixing with water, the volume reduces to the wet or compacted volume used for actual construction.
The mix ratio determines the strength and durability of your concrete. Here are standard ratios for different grades:
| Grade | Mix Ratio (C:S:A) | Common Usage | Strength (MPa) |
|---|---|---|---|
| M10 | 1 : 3 : 6 | Plain concrete, leveling courses | 10 MPa |
| M15 | 1 : 2 : 4 | Foundations, residential footings | 15 MPa |
| M20 | 1 : 1.5 : 3 | Slabs, beams, columns | 20 MPa |
| M25 | 1 : 1 : 2 | Heavy-duty structures, bridges | 25 MPa |
Why Mix Ratio Matters: The correct mix ratio ensures your concrete achieves the required strength and durability. Higher cement content increases strength but also cost. M20 is the most commonly used grade for residential construction.
Each concrete structure requires a different volume formula. Match your project shape below — all measurements must be in the same unit (feet or meters) before calculating.
Slab · Driveway · Patio
V = L × W × T
All in feet · result ÷ 27 = yd³
Column · Sonotube · Pier
V = π × R² × H
All in feet · result ÷ 27 = yd³
Wall · Retaining Wall
V = L × H × T
All in feet · result ÷ 27 = yd³
Fence Post · Deck Pier
V = π × (D/2)² × Depth
+ 20–25% waste · ÷ 27 = yd³
| Structure | Formula (all in feet) | To Get yd³ | Common Projects |
|---|---|---|---|
| Rectangular Slab | Length × Width × Thickness | ÷ 27 | Driveway, patio, floor slab, footing |
| Cylinder / Column | 3.1416 × Radius² × Height | ÷ 27 | Round columns, sonotubes, piers |
| Wall | Length × Height × Thickness | ÷ 27 | Retaining walls, foundation walls |
| Post Hole (round) | 3.1416 × (Diameter ÷ 2)² × Depth | ÷ 27 + 20% | Fence posts, deck piers, sign bases |
Unit tip: All measurements must be in feet before calculating. Convert inches to feet by dividing by 12. Example: 4 inches = 4 ÷ 12 = 0.333 ft
| From | To | Conversion Factor |
|---|---|---|
| 1 Cubic Meter (m³) | Cubic Feet (ft³) | × 35.31 |
| 1 Cubic Yard (yd³) | Cubic Feet (ft³) | × 27 |
| 1 Cubic Meter (m³) | Cubic Yards (yd³) | × 1.308 |
| 1 Cement Bag (50 kg) | Cubic Meters (m³) | ≈ 0.035 m³ |
Water-Cement Ratio
Maintain a water-cement ratio of 0.4 to 0.6 for optimal strength. Too much water weakens concrete; too little makes it unworkable.
Curing Time
Proper curing is critical. Keep concrete moist for at least 7 days. Full strength is typically achieved after 28 days.
Temperature Matters
Pour concrete in temperatures between 50°F-90°F (10°C-32°C). Extreme temperatures affect setting and strength.
Given:
Step-by-Step Calculation:
Volume = L × W × T
Volume = 10 ft × 10 ft × 0.333 ft
Volume = 33.33 cubic feet ≈ 1.23 cubic yards
Final Result:
• Concrete needed: 1.23 yd³
• Cement bags: ~27 bags (50 kg each)
• Sand: ~0.42 tons
• Aggregate: ~0.83 tons
Given:
Step-by-Step Calculation:
Volume = L × W × T
Volume = 20 ft × 3 ft × 0.25 ft
Volume = 15 cubic feet ≈ 0.56 cubic yards
Final Result:
• Concrete needed: 0.56 yd³
• Cement bags: ~12 bags (50 kg each)
• Add 10% extra for waste: 0.62 yd³
Given:
Step-by-Step Calculation (per post):
Volume (cylinder) = π × R² × Depth
Volume = 3.1416 × (0.417 ft)² × 3 ft
Volume = 3.1416 × 0.174 × 3 = 1.64 ft³ per post
Total (10 posts) = 1.64 × 10 = 16.4 ft³ = 0.61 yd³
Final Result:
• Concrete needed: 0.61 yd³ total
• Bags required: ~18 bags of 50 kg (add 20% waste for post holes)
• With 20% waste factor: ~22 bags recommended
💡 Fence post holes need 20–25% extra concrete — cylindrical holes are harder to fill precisely than flat slabs. Better to have 2 extra bags than run short mid-project.
Pro Tip: You can verify these calculations instantly using the calculator above. Simply enter your project dimensions and get accurate results in seconds!
Multiple Structure Types
Calculate concrete for flat slabs, footings, driveways, retaining walls, and round columns or sonotubes — all in one tool.
Imperial & Metric Units
Full support for feet/inches (US) and meters/centimeters (international). Switch systems without recalculating manually.
Results in 3 Volume Units
Output simultaneously in cubic feet, cubic meters, and cubic yards — the three units used by US suppliers, metric countries, and ready-mix trucks.
Cement Bag Estimation
Calculates exact number of 50 kg cement bags needed using the standard 0.035 m³ per bag conversion, adjusted for your selected M-grade mix ratio.
Built-in Cost Estimator
Enter your local price per cubic meter to get an instant total project cost — useful for budgeting before calling a ready-mix supplier.
Copy Results & Download CSV
Copy results to clipboard in one click, or download your calculation as a CSV file for project records, bids, or sharing with contractors.
Calculation History (Last 5)
Automatically saves your last 5 calculations for quick reference across multiple pours or project phases. History clears after 3 days.
Smart Waste Factor Alerts
Automatically recommends 5–10% extra concrete based on your project type — so you never run short during a pour.
The most common question after calculating cubic yards: should you order ready-mix delivery or buy bags from Home Depot / Lowe's? The answer depends on your project size.
| Factor | Ready-Mix Truck | Bagged Concrete |
|---|---|---|
| Best for project size | 1+ cubic yards (27+ ft³) | Under 0.5 yd³ (small repairs) |
| Average cost | $120–$200 per cubic yard | $5–$8 per 80lb bag (≈ $180/yd³ in bags) |
| Minimum order | 1–2 yd³ typical minimum | No minimum |
| Labor | Pour directly — fast | Mix each bag — time intensive |
| Equipment needed | Access for truck (10–12 ft) | Mixer or bucket + drill |
| Strength consistency | Plant-tested, certified PSI | Variable — depends on mixing |
| Weekend availability | Often limited hours | 24/7 at home stores |
| Break-even point | ~1 cubic yard | Better under 0.5 yd³ |
🚛 Choose Ready-Mix if:
🛒 Choose Bagged Concrete if:
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For rectangular slabs, footings, and driveways: Volume = Length × Width × Thickness (all in feet). Divide by 27 to convert cubic feet to cubic yards. For cylindrical columns and sonotubes: Volume = π × Radius² × Height. This calculator applies a dry volume factor of 1.54 automatically, which accounts for the compaction of dry cement, sand, and aggregate after water is added. Always add 5–10% to your calculated volume for waste.
One standard 50 kg cement bag covers approximately 0.035 cubic meters of concrete (about 1.23 ft³). For 1 cubic meter of M20 concrete (1:1.5:3 mix ratio), you need approximately 8 bags of cement, 0.42 m³ of sand, and 0.83 m³ of aggregate. For M15 (1:2:4), you need approximately 6.5 bags per cubic meter. This calculator shows exact bag counts for your chosen mix ratio and project dimensions.
Mix ratio represents the proportion of cement : sand : coarse aggregate by volume. A 1:2:4 mix (M15 grade) means 1 part cement, 2 parts sand, and 4 parts 20mm aggregate. M20 grade uses 1:1.5:3 and is the most common choice for residential slabs, driveways, and columns in the US and India. Higher cement ratios increase compressive strength but also cost — only use M25 or higher for structural load-bearing elements.
Depth has a direct linear effect on concrete volume. A 10 × 10 ft slab at 4 inches thick needs 1.23 yd³. At 6 inches thick, the same slab needs 1.85 yd³ — a 50% increase. US residential driveways require a minimum of 4 inches (ACI 318), while heavy vehicle driveways need 6 inches. Patios and sidewalks typically use 3.5 to 4 inches. Always verify depth requirements with your local building code before ordering.
Yes. This calculator uses the industry-standard dry volume factor of 1.54 and nominal mix ratios defined in ACI 211.1 (American Concrete Institute) and IS 456:2000 (Indian Standard). These are the same standards used by professional estimation software. That said, always order 5–10% extra concrete to account for spillage, uneven subgrade, and form variations. For load-bearing foundations or structural columns, consult a licensed structural engineer before finalizing quantities.
Waste factor is the percentage of extra concrete you should order beyond your calculated volume to account for real-world losses. The correct waste factor depends on your project type: flat slabs and patios need 5–8% extra; driveways 8–10%; foundation footings 10–15%; concrete columns 15–20%; and fence post holes 20–25%. This calculator automatically recommends a waste factor based on your selected shape. When ordering ready-mix, always round up to the nearest 0.25 yd³.
Ready-mix delivery becomes more cost-effective and practical for projects over 1 cubic yard (27 ft³). Below 0.5 yd³ — such as fence posts, small repairs, or filling gaps — bagged concrete from a hardware store is more practical. Between 0.5 and 1.0 yd³, both options are viable: ready-mix offers strength consistency and speed, while bags give you flexibility to work at your own pace. Ready-mix trucks typically require a minimum order of 1–2 yd³ and need vehicle access within 10–15 feet of the pour site.
Yes. Switch the shape selector to 'Column' mode and enter the diameter and height of your cylindrical structure. The calculator uses the formula V = π × (D/2)² × Height to compute volume. This works for sonotubes, round columns, deck piers, and fence post holes. For fence posts, add 20–25% extra to your calculated volume — cylindrical holes in soil are harder to fill precisely than flat slabs, and running short mid-pour is a common and costly problem.