Concrete Calculator
Enter dimensions to get cubic yards and 60 lb bag counts for your slab or footing.
10 × 10 × 4 in slab ≈ 1.23 yd³ (with 10% waste).
What the Concrete Calculator does
The Concrete Calculator turns simple project measurements into an accurate estimate for concrete. Enter your dimensions, choose a depth, and get volume, weight, bag counts, and (when priced) delivered cost.
It is designed for real jobs, not textbook problems. The defaults follow industry conventions used by landscapers, contractors, and DIY homeowners in the United States, and the results can be switched between imperial and metric units where the inputs support it.
- Volume in cubic feet, cubic yards, and cubic meters
- Weight in pounds, tons, and metric tonnes
- Bag counts for the most common bagged sizes
- Optional waste/compaction allowance so you don't run short
How to measure your project
Measure length and width in feet at the widest points, and depth in inches. For irregular shapes, break the area into rectangles or circles, run the Concrete Calculator on each piece, and add the results together.
For load-bearing surfaces (driveways, walkways, and patios) add 10–20% compaction so the finished depth matches the plan. For decorative applications (garden beds, borders) a 5–10% waste factor is usually enough.
Tips for accurate estimates
Weight varies with moisture, particle size, and mineral density. When ordering by weight, ask the supplier for their published density in tons per cubic yard and match it to the material you actually chose.
When ordering by volume, remember that suppliers deliver by loose cubic yards — after compaction the same yardage covers less area. Building in a small buffer is almost always cheaper than a second delivery.