Calculate how much concrete you need for slabs, footings, posts, and other projects. Get results in cubic yards, bags, and estimated cost.
Wet concrete weighs approximately 150 lbs per cubic foot or about 4,050 lbs per cubic yard. After curing, it weighs slightly less (around 145 lbs/ft³) due to water evaporation.
For projects under 1 cubic yard, bags are practical and give you control over timing. For 1-2 yards, either can work but ready-mix saves significant labor. Over 2 yards, ready-mix is almost always more economical and practical. A cubic yard takes about 45 80-lb bags—that's a lot of mixing!
Standard garage floors are 4" thick with 3000-3500 PSI concrete. If you'll have heavy vehicles, equipment, or a vehicle lift, consider 5-6" thickness with fiber mesh or rebar reinforcement. Always use proper sub-base preparation.
For most garage and shop floors, welded wire mesh (WWM) or fiber reinforcement is adequate. Rebar is needed for structural applications, thicker slabs, or where heavy point loads occur. Footings typically require rebar per code requirements.