Online Concrete Calculator - Volume & Bag Estimator
Calculate Concrete Volume & Bags
How to use: Enter the length and width in feet, and thickness in inches. The calculator automatically adds the waste factor (default 10%) to ensure you have enough concrete.
Note: One 80lb bag yields approximately 0.6 cubic feet. One 60lb bag yields approximately 0.45 cubic feet.
Frequently Asked Questions
How many cubic feet in an 80lb bag of concrete?
An 80lb bag of concrete yields approximately 0.6 cubic feet when mixed. This means you need about 1.67 bags per cubic foot, or 45 bags per cubic yard.
How do I calculate concrete for a slab?
Calculate slab concrete by multiplying length × width × thickness (all in feet). Divide by 27 to get cubic yards. Add 10% for waste. Example: 10ft × 10ft × 0.33ft = 33 cubic feet ÷ 27 = 1.22 cubic yards.
How much does a yard of concrete weigh?
One cubic yard of concrete weighs approximately 4,000 pounds (2 tons) when wet. Dry weight is around 3,600 pounds depending on aggregate mix.