Concrete Calculator — Cubic Yards, Bags & Cost

How to use

1. Pick your shape: slab, round footing or steps, and enter the dimensions.
2. Keep the 10% waste toggle on unless the form is dead-level and generous.
3. Read cubic yards, then bag counts for whichever bag size you can actually haul.
4. Optional: enter bag prices or delivered price per yard to compare both routes.

About this tool

Order too little concrete and the pour turns into a cold joint; order too much and it is money in a dumpster. This calculator handles the three pours people actually attempt: rectangular slabs, round footings and simple steps, converting your dimensions into cubic feet, cubic yards and cubic meters, then into 80, 60 and 40 lb bag counts using real yield figures. A 10% waste toggle covers the spillage and uneven subgrade every real pour has, and optional cost fields let you compare buying bags against having a ready-mix truck show up. Curing matters as much as ordering — keep the slab damp for five to seven days and keep vehicles off it for a week. All of the math runs in your browser.

FAQ

Rate this tool

Your rating stays in this browser (local storage) — nothing is sent to any server.