How much to buy, worked out from the data sheet

Tell us the size of the job and get a shopping list in the units the store sells: bags, gallons, cubic yards. Every number comes from a published manufacturer yield or a university guide, and each page shows its math.

• Concrete CalculatorBags of 40, 50, 60 or 80 lb mix (or cubic yards) for a slab or footing.
• Fence Post Concrete CalculatorHow many bags to set your posts, by post size and hole.
• Mulch CalculatorBags or cubic yards of mulch for your beds.
• Paint CalculatorGallons of paint for a room, minus doors and windows.

Why trust these numbers?

Most "how many bags" answers online guess at what a bag yields. We use the figure printed on the manufacturer's data sheet, link to it, and show the arithmetic, so you can check it against the bag in front of you. Where sources disagree, the page says so.

Results update as you type, and the address bar keeps your numbers so you can bookmark or share a calculation from the store aisle.