Free concrete yardage calculator.
This free concrete yardage calculator returns the cubic yards needed for slabs, footings, columns (rectangular or round), and walls, with a configurable waste percentage. Built for fast pre-order sizing during a takeoff. Toggle Imperial or Metric. For bidding-grade concrete takeoff from drawings, use BidScreen XL.
Concrete needed
Want this measured straight from your PDF instead? BidScreen XL adds the same math to Microsoft Excel — trace the drawing, the quantity lands as a live cell.
Volume = length × width × thickness, mostly.
Slab, footing, rectangular column, and wall volumes are all three-dimension products: length × width × thickness (or depth, or height). Divide cubic feet by 27 to get cubic yards. In metric, dimensions in meters give cubic meters directly. One cubic yard is about 0.7646 cubic meters.
Round column volume is π × (diameter / 2)² × height. The column inputs accept a count; the calculator multiplies the per-column volume by the count for the total. For a foundation with 8 round columns of the same size, enter the count once.
The waste percentage over-orders the geometric volume to cover spillage, formwork voids, and minor scope changes. 10% is a reasonable default; complex pours need 12-15%. Ready-mix suppliers usually deliver in 1/4 yard increments, so round the with-waste figure up to the next quarter yard when calling it in.
For each formula in detail, ready-mix ordering practice, and the short-load fee tradeoff, see the in-depth guide How to calculate concrete yardage.
Frequently asked
How much waste should I add to my concrete order?
5-10% for simple geometries (large slabs, straight walls). 10-15% for complex pours (curved walls, multiple columns, congested reinforcement). The 10% default works for most residential and light commercial pours.
How do I calculate concrete for stairs or curved geometries?
Break the shape into rectangular pieces. A stair tread is approximately length × tread depth × thickness; a riser is length × riser height × thickness. Add the pieces and round up. Curved walls can be approximated as a series of straight segments.
What's the difference between net volume and with-waste volume?
Net volume is the calculated geometric volume of concrete. With-waste adds your waste percentage on top, which is what you actually order from the ready-mix supplier. Ready-mix is usually sold in 1/4 yard increments; round up to the next quarter yard.
How accurate is this for a bid?
Accurate for the geometric volume. The waste percentage is a judgment call that varies by project. For competitive bidding on complex pours, BidScreen XL traces the actual slab and footing outlines from your PDF and pulls the formula-backed quantity directly into your Excel estimating workbook.
Does this account for rebar or formwork volume?
No. Rebar displacement is usually rolled into the waste percentage (3-5% on its own). Formwork is a separate line item. The calculator returns the gross concrete volume; deductions for embeds are negligible for typical structural concrete.
BidScreen XL traces concrete from the drawing.
Skip the geometric inputs. BidScreen XL adds PDF and CAD measurement to Microsoft Excel; trace the slab, footing, or column outline on the drawing and the quantity lands as a live formula in your bid workbook. $400 a year or $799 perpetual.