Concrete Calculators
Figure out exactly how many bags — or how many cubic yards — a pour needs, before you're standing at the register guessing.
Patios, walkways, shed floors and driveways. Enter length, width and thickness for bags or cubic yards.
Open calculator →The strip footing under a wall or slab edge. Enter run length, width and thickness.
Open calculator →Round form tubes for deck and post footings. Enter diameter, height and tube count.
Open calculator →Bags per post hole, subtracting the post's own volume from the hole. Enter post count and hole size.
Open calculator →Foundation and stem walls. Enter wall length, height and thickness.
Open calculator →Landscape edging or driveway curb. Enter run length, width and height.
Open calculator →Outdoor concrete stairs. Enter width, rise, run and number of steps.
Open calculator →How much concrete do I need?
Every calculator here starts from the same volume math: length × width (or the shape's area) × thickness, converted to cubic feet, then to cubic yards or bags. The difference between them is the shape — a slab or poured wall is a flat rectangle, a footing or curb is a long narrow strip, a sonotube is a cylinder, steps are a stack of rectangles, and a fence post hole is a cylinder with the post's own volume subtracted out.
As a rough rule, bags make sense up to about 1 to 2 cubic yards. Past that, a ready-mix delivery is usually faster and cheaper — see concrete cost per yard to compare.