Concrete Calculator
Calculate how much concrete you need for your project. Get results in cubic yards, cubic feet, and number of bags.
Slab Dimensions
Concrete Needed
Cubic Yards
1.23
Cubic Feet
33.3
Cubic Meters
0.94
60lb Bags
75
80lb Bags
56
Add 10-15% extra for waste and spillage. Order slightly more than calculated.
How to Calculate Concrete
The concrete calculator formula: Volume = Length × Width × Depth. Convert depth from inches to feet by dividing by 12, then divide cubic feet by 27 to get cubic yards.
Concrete Calculator FAQ
How much concrete do I need?▼
Calculate volume: Length × Width × Depth (in feet). Divide cubic feet by 27 to get cubic yards. Add 10% for waste. Our calculator does this automatically.
How many bags of concrete for 1 cubic yard?▼
You need approximately 45 bags of 80lb concrete mix or 60 bags of 60lb mix per cubic yard.
How thick should a concrete slab be?▼
Standard residential slabs are 4 inches thick. Driveways should be 5-6 inches. Heavy-duty areas may need 6-8 inches. Always check local building codes.