Concrete Calculator
Estimate Concrete Volume & Weight for All Project Types
📐 Pro Tips for Accurate Estimates:
Measure all dimensions accurately—even small errors compound in volume calculations. Use a 25-meter measuring tape for large projects. Double-check measurements before ordering. Always add 10-15% extra to calculated amounts for waste and spillage. Consider ground irregularities when measuring depth.
Slabs, Square Footings, or Walls
✅ Concrete Required:
Hole, Column, or Round Footing
✅ Concrete Required:
Stairs
✅ Concrete Required:
Curb and Gutter Barrier
✅ Concrete Required:
🔨 What is Concrete?
Concrete is a composite material made of coarse aggregates (sand, gravel, crushed stone) bonded with cement. Portland cement is the most commonly used cement in concrete, mortar, and plasters. The mixture typically includes water, aggregate, and cement, which harden together over time.
Concrete Composition:- Cement (10-15%): Binds materials together
- Sand (25-30%): Fine aggregate for workability
- Gravel (40-50%): Coarse aggregate for strength
- Water (15-20%): Activates cement for hydration
- Air (5-8%): Entrapped or intentional for durability
- Bagged Concrete: 60-pound or 80-pound bags, mixed on-site (suitable for small projects)
- Ready-Mix Concrete: Delivered by truck, professionally mixed (best for large projects)
- Precast Concrete: Factory-made products like concrete blocks and panels
Curing is the hardening process after placement. Concrete reaches approximately 50% strength in 7 days and 90% strength in 28 days. Final strengthening can continue for up to 3 years. Proper moisture retention during early curing increases final strength by up to 50%.
📋 Concrete Thickness by Application
| Application | Recommended Thickness | Common Use |
|---|---|---|
| Patio/Sidewalk | 5-10 cm (2-4 in) | Light foot traffic, low loads |
| Driveway | 10-15 cm (4-6 in) | Vehicle traffic, moderate loads |
| Parking Lot | 12-18 cm (5-7 in) | Heavy vehicle traffic |
| Garage Floor | 10-12 cm (4-5 in) | Light vehicle storage |
| Industrial Floor | 15-20 cm (6-8 in) | Heavy machinery, equipment |
| Foundation Slab | 10-15 cm (4-6 in) | Building support, load-bearing |
| Curb/Gutter | 4-5 cm (1.5-2 in) | Road edge, drainage |
⚖️ Concrete Weight & Density Reference
| Concrete Type | Density (kg/m³) | Density (lb/yd³) | Notes |
|---|---|---|---|
| Standard Concrete | 2,300-2,400 | 3,400-3,600 | Most common type, general use |
| Lightweight Concrete | 1,400-1,900 | 2,100-2,850 | Reduced weight, good insulation |
| Heavy Concrete | 2,500-3,000 | 3,750-4,500 | Radiation shielding, higher density |
| Air-Entrained Concrete | 2,200-2,350 | 3,300-3,500 | Contains air bubbles, freeze-thaw resistant |
Standard Formula: Weight = Volume (m³) × 2,400 (kg/m³) for typical concrete
❓ Frequently Asked Questions
How accurate is this concrete calculator?
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The calculator provides highly accurate estimates for standard rectangular and cylindrical shapes. Accuracy depends on measurement precision. Real-world variables like ground irregularities, waste, and spillage require adding 10-15% extra. Always verify measurements twice before ordering concrete.
Should I round up or down when calculating concrete needed?
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Always round up. It's better to have leftover concrete than to run short mid-project. Add 10-15% safety margin to your calculated total. Ready-mix trucks typically deliver in 0.5 cubic yard increments, so round to nearest 0.5 cubic yards.
What is the difference between concrete, cement, and mortar?
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Cement is a powder that binds materials. Concrete is cement + aggregates (sand, gravel, stone). Mortar is cement + sand + water, used for joining bricks/blocks. Concrete is strongest; mortar is more flexible for masonry work.
How long does concrete take to cure completely?
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Concrete typically reaches 50% strength in 7 days, 90% in 28 days. Full strength takes 3 years, but practical strength for most projects is achieved in 28 days. Proper curing (keeping concrete moist) is critical for achieving rated strength.
Can I order concrete in small quantities?
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Yes, multiple options exist. For very small projects (under 0.5 cubic meters): mix bags on-site. For small-medium projects: mini ready-mix trucks deliver 2-4 cubic meters. For larger projects: standard trucks deliver 10+ cubic meters. Always confirm minimum order requirements with suppliers.
What weather conditions affect concrete placement?
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Ideal conditions: 15-25°C (60-77°F), moderate humidity, no rain. Too hot: concrete sets too quickly. Too cold: hydration slows significantly (below 5°C is problematic). Rain: dilutes surface causing weakness. Plan projects for mild weather and protect from precipitation during curing.
What tools do I need for concrete placement?
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Essential tools: concrete mixer or ready-mix truck, wheelbarrow, shovel, level, screed board, broom (for finish), concrete trowel. For finishing: edger tool, broom for non-slip surface. For large projects: concrete vibrator prevents air pockets. Proper tools ensure quality results.
How do I calculate concrete for irregular shapes?
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Break irregular shapes into regular sections (rectangles, circles, triangles). Calculate each section separately using standard formulas, then add totals together. For complex shapes, use grid method: divide into squares, average the depths at multiple points, then multiply by area.