Ready-mix delivery
Concrete Calculator
Calculate concrete volume, waste allowance, premix bag count, and optional material cost for slabs, footings, walls, and columns.
✓Multiple shapes✓US & metric units✓Waste allowance✓Bag estimate
Visual previewProportional view
Recommended order
Net volume
With waste
How should you buy it?Compare practical purchase options
Premix bags
Estimate only. Ready-mix prices shown here exclude delivery fees, short-load fees, taxes, pumping, reinforcement, and labor. Local codes, site conditions, and supplier specifications can affect actual requirements.
How this concrete calculator works
The calculator converts each dimension to feet, calculates the project volume, applies your selected waste allowance, then converts that volume into cubic yards, cubic feet, cubic meters, and an estimated number of premix bags.
Slabs, footings, and walls
Volume = length × width × thickness
Round columns
Volume = π × (diameter ÷ 2)² × height
A waste allowance is added after the geometric volume is calculated. Ten percent is a practical starting point for many small DIY estimates, but actual needs vary by site and project.