ConcreteQty

All-in-one concrete planner

Concrete Calculator

Calculate slabs, post holes, footings, walls, columns, bag counts, waste, and an order-ready quantity.

Project

LENGTHWIDTHTHICKNESS

Formula

How the result is calculated

Volume = measured area × concrete thickness. ConcreteQty converts the result to cubic yards or cubic meters, then applies waste and supplier rounding separately.

Worked example

Check the order logic

A 12 × 10 ft slab at 4 in thick contains 1.48 yd³ before waste. With a 10% allowance and 0.25 yd³ ordering increments, the displayed order quantity is 1.75 yd³.

Assumptions

Waste and supplier rounding stay editable

The launch defaults are 10% waste and upward rounding to 0.25 yd³ or 0.10 m³. Open “Adjust assumptions and costs” to use your supplier’s increment, actual prices, density, truck capacity, or product bag yield.

Questions

What this calculator does

Does the result include waste?

Yes. The default is 10%, and the calculated volume remains visible separately.

Can I combine several pours?

Yes. Add sections for slabs, footings, walls, post holes, or columns and ConcreteQty totals them.

Does this design the concrete structure?

No. It calculates quantity and purchasing estimates only.

Bag yields follow the cited manufacturer data. See sources and review dates.