Show HN: Concrete Calculator – Estimate Cubic Yards, Bags and Cost Posted by struy on Friday September 25, 2026 @09:37AM from the show-hn dept. https://concretemixcalc.com Free concrete calculator: enter length, width and thickness to get cubic yards, 80/60/40-lb bag counts and estimated cost — results update as you type. ( 1 comment | on HN )