🧱 Concrete Calculator
Calculate exactly how much concrete you need for slabs, footings, columns, walls, and stairs. Get accurate cubic yards and bag counts.
Calculate exactly how much concrete you need for slabs, footings, columns, walls, and stairs. Get accurate cubic yards and bag counts.
Accurate concrete estimation is crucial for any construction project. Order too little and you'll have delays; order too much and you waste money. This calculator helps you get it right.
For large projects, order 5-10% extra. For small projects or complex shapes, order 10-15% extra. It's always better to have a little left over than to run short mid-pour.
Standard for pedestrian traffic
Adequate for furniture and foot traffic
Standard passenger vehicles
RVs, boats, trailers
Based on vehicle weight
Depends on load and soil
| Mix Type | PSI Strength | Best For |
|---|---|---|
| Standard Mix | 2,500 PSI | General purpose, patios, sidewalks |
| Crack-Resistant | 4,000 PSI | Driveways, high-traffic areas |
| High-Strength | 5,000+ PSI | Foundations, commercial applications |
| Fast-Setting | 4,000 PSI | Post setting, repairs (sets in 20-40 min) |
| Fiber-Reinforced | 4,000+ PSI | Floors, countertops, thin applications |
Bagged concrete: ~$4-6 per 80 lb bag ($300-450 per cubic yard)
Ready-mix delivered: ~$125-175 per cubic yard (plus delivery fee)
Standard concrete coverage varies by thickness. Use this table to estimate material for common residential projects. A standard 60 lb bag of concrete mix covers approximately 0.45 cubic feet when mixed:
| Thickness | 100 sq ft coverage | 60 lb bags needed | 80 lb bags needed | Cubic Yards |
|---|---|---|---|---|
| 2 inches (walkway) | 100 sq ft | 37 | 28 | 0.62 |
| 3 inches (patio) | 100 sq ft | 56 | 42 | 0.93 |
| 4 inches (driveway/slab) | 100 sq ft | 75 | 56 | 1.23 |
| 6 inches (heavy pad) | 100 sq ft | 112 | 84 | 1.85 |
| Application | Cement : Sand : Aggregate | Target PSI |
|---|---|---|
| Footings / foundations | 1 : 3 : 3 | 3,000×4,000 PSI |
| Sidewalks / driveways | 1 : 2 : 3 | 3,500×4,000 PSI |
| Structural beams/columns | 1 : 1.5 : 3 | 4,000×5,000 PSI |
| Decorative / repair | 1 : 3 : 0 | 2,000×2,500 PSI |