Concrete calculators
Ten tools that go deep into one category — slab, bags per yard, fence post, footing, driveway cost, stairs, column, gravel base, rebar, mix ratio. Every page gives you a full materials estimate, not just a single number.
Concrete Slab Calculator
Enter your slab dimensions and get bag counts, ready-mix yards, and a cost estimate.
Bags of Concrete Per Yard
Convert cubic yards to bag counts at 40, 60, and 80 lb — with waste allowance and cost comparison.
Fence Post Concrete Calculator
Enter post size, hole depth, and post count — get the total concrete needed in bags and cubic feet.
Concrete Footing Calculator
Strip or pad footing — enter length, width, and thickness to get cubic yards, bag counts, and cost.
Concrete Driveway Cost Calculator
Enter length, width, and price per square foot — get a complete driveway cost estimate with breakdown.
Concrete Stairs Calculator
Enter width, riser height, tread depth, and step count — get concrete volume in cubic yards and bags.
Concrete Column Calculator
Cylindrical column or pier — enter diameter, height, and quantity for cubic yards and bag counts.
Gravel Base for Concrete Slab Calculator
Enter slab area and base depth — get tons and cubic yards of crushed stone needed for the sub-base.
Rebar Spacing Calculator
Enter slab dimensions and grid spacing — get total linear feet of #4 bar, piece count, and weight.
Concrete Mix Ratio Calculator
Enter total volume and mix ratio — get cement bags, sand, and aggregate quantities for site-mixed concrete.
How to use these calculators
- 1Pick a preset at the top of any tool page — common scenarios like a 10×10 shed base or a 24×24 garage. Or type your own dimensions directly.
- 2Watch results update live as you type — no Calculate button. The largest number on the page is your primary answer (e.g. "1.5 yd³" or "62 bags").
- 3Adjust the waste slider if your forms aren't perfectly level. The default 10% covers spillage, over-excavation, and partial-bag leftovers.
- 4Edit price assumptions to match your local quotes — expand the collapsed "Edit price assumptions" block and enter your bag price, ready-mix price per yard, and gravel price per ton.
- 5Copy, share, or print your result. The share link encodes your inputs in the URL so you can send the exact calculation to a client or save it for later.