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Concrete Calculator

Get cubic yards, bags and ready-mix truck loads for slabs, footings and driveways.

Project dimensions

Tip: add 5–10% extra for spillage and uneven subgrade.

You'll need

Concrete volume0 yd³
Cubic feet0
60 lb bags0
80 lb bags0
Ready-mix trucks (10 yd³)0

Includes your waste factor. Bag counts rounded up to whole bags.

How it works

Volume = length × width × thickness, converted to cubic yards (÷ 27). We then convert to bags using standard yields — 0.45 ft³ per 60 lb bag and 0.60 ft³ per 80 lb bag — and to truck loads at 10 yd³ per ready-mix truck.

Rule of thumb: Order ready-mix for anything over ~1 cubic yard. Below that, bagged concrete is usually cheaper and easier.

Get your concrete supplies

Bagged mix, ready-mix and tools from trusted suppliers and local pros.

Good to know

Concrete FAQs

How much concrete for a 10x10 slab?

A 10×10 ft slab at 4 inches thick needs about 1.23 cubic yards (33.3 ft³) — roughly 74 sixty-pound bags or 56 eighty-pound bags.

How many 80 lb bags make a yard?

45 eighty-pound bags make one cubic yard. Each bag yields 0.60 ft³ and a yard is 27 ft³.

60 lb or 80 lb bags?

80 lb bags are cheaper per yard and mean fewer bags on big pours. 60 lb bags are lighter and easier for small or solo jobs.

How thick should concrete be?

4″ for sidewalks and patios, 4–6″ for driveways and garage floors, 6–8″ for heavy vehicles, 8–12″ for foundations.

Ready-mix or bags?

Ready-mix is cheaper and more consistent above ~1 cubic yard. Bags suit small or phased jobs.