Concrete Calculator
Estimate concrete volume, waste, bag count, and material cost for slabs or round columns.
Inputs
Results update as you edit.
Concrete needed
1.63 yd³
Results update as the calculator inputs change.
Base volume
1.48 yd³
Cubic feet
40 ft³
80 lb bag estimate
74
Estimated material cost
$260.74
How to Calculate Concrete Volume
How to Estimate Concrete for a Project
Concrete estimates convert project dimensions into cubic volume, then add waste and optionally estimate bags or cost. Accurate measurements and consistent units are essential.
What Affects Concrete Quantity?
Concrete Estimating Steps
Volume
Calculate cubic feet, then convert to cubic yards by dividing by 27.
Bag Count
Estimate bags from bag yield when using premixed bags.
Cost Estimate
Multiply required volume by price to estimate material cost.
Frequently Asked Questions
How do I calculate cubic yards of concrete?
Calculate cubic feet from dimensions, then divide by 27 because one cubic yard equals 27 cubic feet.
Should I add extra concrete?
Usually yes. A waste factor helps cover spillage, uneven forms, and measurement error.
Why does thickness matter so much?
Thickness is one of the volume dimensions, so increasing it raises the entire slab volume.
Does this include reinforcement or labor?
No. It estimates concrete material volume and optional material cost, not rebar, forms, delivery, tools, or labor.
Should I order ready-mix or bags?
Small projects may use bags. Larger pours often need ready-mix delivery, but minimum orders and delivery fees vary.