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Concrete Calculator

Enter the slab size and thickness to see how much concrete to order, or how many bags to mix.

How it's figured

Cubic yards = length × width × (thickness ÷ 12) ÷ 27. Add 5–10% for uneven grade and spillage. An 80 lb bag makes about 0.6 cu ft; a 60 lb bag about 0.45 cu ft. Over about 1 yard, ready-mix is usually cheaper and faster than bags.

Want this for every job, all year?

The Concrete Flatwork Estimator does this and much more in Google Sheets and Excel: saved, organized and protected so nothing breaks. Buy once, $27.

See the Concrete Flatwork Estimator

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