Guides
Quick answers, with the math shown.
Reference charts for the questions that come up most often. Every number comes from the same formulas as our calculators.
How Much Concrete for a Slab
Cubic yards and bags for 10×10, 12×12, 20×20 and other common slabs at 4, 5 and 6 inches thick.
How Many Bags of Concrete per Yard
40, 60 and 80 lb bags per cubic yard, and when a ready-mix truck becomes cheaper than bags.
How Many Bags of Concrete per Fence Post
Bags per post by hole size and depth for 4×4 and 6×6 posts, and how to size the hole.
Concrete Cost Guide
What concrete costs per cubic yard, per bag and per square foot — and the extras that add to the bill.