Concrete Calculator
Free concrete calculator for slabs, footings, tubes, curbs, and stairs. Estimate volume, cubic yards or meters, and 60lb / 80lb bags in seconds.
Calculators
How to Use
Measure length × width × thickness, or diameter × depth depending on shape.
Fill in your measurements and choose metric (cm, m) or imperial (ft, in, yd).
See concrete volume, weight, and required bags instantly.
Save results to the floating Dock for cost estimation and comparison.
Concrete Calculator FAQ
Q1How many bags are in 1 cubic yard?›
One cubic yard of concrete requires about 45 bags of 60lb mix or about 60 bags of 80lb mix. When using a concrete calculator, always add 5–10% extra for waste and ground variations.
Q2How thick should a patio slab be?›
Most residential patio slabs are around 4 inches thick. For driveways or heavy loads, a concrete calculator can help estimate volume, but thickness usually increases to 5–6 inches to prevent cracking.
Q360lb vs 80lb concrete bags?›
A 60lb bag of concrete yields about 0.45 cubic feet, while an 80lb bag yields around 0.60 cubic feet. Concrete calculators help decide which size is more efficient for your project. Choose 60lb bags for easier handling, or 80lb for fewer bags overall.
Q4How do I calculate concrete for footings or columns?›
For cylindrical shapes like footings or columns, measure the diameter and depth, then enter values into a concrete footing calculator to get the volume in cubic yards and required bag count.
Q5Do I need rebar or reinforcement in my slab?›
A concrete calculator gives volume, but reinforcement depends on use case. Small patios may only need wire mesh, while larger slabs and driveways usually require rebar or fiber reinforcement for strength.