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Shopping for bagged mix? Select your bag size (80 lb is the most common at big-box stores) and enter your project size. We convert cubic feet to bags using manufacturer yields.

Frequently asked questions

How many cubic feet in an 80 lb bag?
Manufacturer specs typically list ~0.60 ft³ per 80 lb bag (Quikrete/Sakrete). 60 lb ≈ 0.45 ft³; 40 lb ≈ 0.30 ft³. Select your bag size in the calculator.
How many 80 lb concrete bags do I need?
Divide your volume in cubic feet by the bag yield (80 lb ≈ 0.60 ft³ per bag), add your waste factor, then round up. Our calculator does this live — e.g. a 12×10×4 in slab with 10% waste needs 74 bags.
Should I buy bags or ready-mix?
Small jobs under ~1 yd³ are usually cheaper and easier with bags. Larger slabs and driveways are ordered by the cubic yard from a ready-mix supplier. We show both bag count and order-ready yards.