Concrete Calculator: Slab, Circle & Column

Estimate concrete volume, cubic yards or cubic metres, and bags needed for slabs, round pads and columns. Works offline.

Concrete Calculator works out how much concrete you need before you buy or order. Pick a shape, enter the sizes and read the result straight away: - Rectangular slab: length, width and thickness - Round pad: diameter and thickness - Round column: diameter and height What you get: - Volume in cubic feet or cubic metres - Volume with a waste allowance (10% by default, editable) - Cubic yards (or cubic metres) of ready-mix to order - Number of bags to buy for common bag sizes (40, 60, 80 lb or 20, 25, 40 kg) - Optional cost estimates from a price per bag or a ready-mix price Switch between feet and inches or metric units at any time. The yield per bag is editable, so you can enter the figure printed on your own bag. Your last settings are remembered on your device. The extension runs entirely in the popup. It needs no permissions, makes no network requests and collects no data. Results are estimates. Always check the yield on your bag and confirm quantities with your supplier. A small link in the popup points to more free calculators at saasnm.com.