Concrete Calculator
Estimate concrete volume and bags needed.
Frequently Asked Questions
How many bags of concrete do I need per cubic yard? +
A cubic yard of concrete requires approximately 45 bags of 80lb mix or 60 bags of 60lb mix. The exact count varies slightly by brand, so these estimates include a small buffer.
How do I calculate concrete for a round column? +
Use the formula: volume = pi x radius squared x height. Enter the column diameter and height in this calculator and it handles the math for you, converting to cubic yards and bag counts.
Should I order extra concrete beyond the calculated amount? +
Yes. Most contractors recommend ordering 5-10% extra to account for spillage, uneven subgrade, and form variations. For complex pours like stairs, consider 10-15% extra.
What is the difference between concrete depth in inches vs feet? +
Slab and footing depth is typically measured in inches (common depths: 4, 6, or 8 inches). This calculator accepts inches for depth and converts to feet internally for the cubic yard calculation.