Concrete Calculator

7-in-1: Slab • Footing • Post Holes • Cylinders Curb • Bags • Mix Ratio

Pick a mode, enter dimensions, and get volume + bag estimates (print-safe).

Tip: Results appear below the button. Changing modes hides results automatically.
Slab Volume
Calculate cubic yards / feet for a rectangular slab.

Dimensions

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Typical: 5–12% depending on forms, grade, and overage policy.
Footing Volume
Calculate concrete volume for a continuous strip footing.

Dimensions

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Post Holes (Rectangular)
Calculate total volume for multiple rectangular post holes.

Hole Count

Dimensions

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Cylinders (Round)
Calculate volume for round piers / sonotubes.

Count + Size

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Curb Volume
Calculate volume for curbs (length × width × height).

Dimensions

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Bags Estimator
Estimate bag count from volume (cubic feet or cubic yards).

Volume Input

Bag Type

Mix Ratio Guide
Quick guidance for common concrete mix ratios (by volume).

Common Ratios

These are quick-reference starting points. Always follow local code and manufacturer instructions.

Use Case Ratio (Cement : Sand : Gravel)
General purpose 1 : 2 : 3
Stronger / structural 1 : 1.5 : 3
Footings / slabs (typ.) 1 : 2 : 4