Question, suggestion or bug? Send a message - we reply within 1-2 business days.
Curious who reads these messages? See the authors page.
Most messages worth writing are about a figure that does not match what you saw at the store or on the job. If that is why you are here, tell us which calculator or guide you were using, the exact dimensions and material you entered (bag size, mix, gravel depth, or slab thickness), the result the tool gave you, and the number you expected instead. With those four things we can usually re-run the formula the same day and either fix the page or explain the gap, which is most often a waste factor the tool already builds in or a bag yield that differs by brand.
Constants like bag yields, aggregate density, and code minimums are listed with their source on the editorial standards page. If a Quikrete or Sakrete data sheet has changed, or a local code section we cite has been superseded, point us at the current document and we will update the constant and every page that uses it. Bagged-mix and ready-mix prices move with the market, so a price on this site is checked periodically rather than in real time; if you have a fresher, dated price from a major retailer, send it along.
Response time is typically one to two business days. We cannot inspect your job site or tell you whether your subgrade, forms, or reinforcement plan is adequate; that call belongs to your contractor or local building department.