Concrete Demolition Calculator

Instantly calculate concrete volume, cubic yards, and required 80‑lb bags for demolition—free and instant results.

  • Free
  • No sign-up
  • Instant results

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How to use it

  1. Enter length (ft), width (ft), and thickness (in).
  2. Click “Calculate” to see cubic feet, yards, and bag count.
  3. Review the results and round up for ordering.

Concrete Demolition Calculator lets you instantly see how much concrete you’ll remove and how many mix bags you’ll need for a new pour. Enter the slab’s length, width, and thickness, and the tool converts those dimensions to cubic feet, then to cubic yards for hauling and to 80‑lb bags using the standard 0.6 ft³ per bag. Knowing the exact volume helps you avoid costly over‑orders or shortfalls, plan waste disposal, and price the job accurately. The results appear in three columns: total cubic feet, equivalent cubic yards, and required bags. Use the cubic‑yard figure to request dump‑truck quotes, and the bag count to order the right amount of mix. All calculations are done in the browser, so your data stays private and you get the numbers instantly.

Pro tips

  • Add 10% extra for breakage and spillage.
  • Round bag count up to the next whole bag.
  • Order concrete mix a day early to avoid delays.
  • Double‑check thickness conversion from inches to feet.

Real-life examples

  • A homeowner planning to replace a 12‑ft patio slab.
  • A contractor estimating material for a garage floor demolition.
  • A landscape crew removing a walkway to calculate disposal volume.

Case study

Mike, a small‑business contractor, entered his 10 ft × 12 ft × 4 in slab and saw 40 ft³, 1.48 yd³, and 67 bags. He ordered 70 bags, avoided a costly shortfall, and completed the job on schedule.

Frequently asked questions

How do I convert thickness from inches to feet?
Divide the inches by 12; the calculator does this automatically.
Why does the bag count show a fraction?
Bags are shown in exact volume; round up to the next whole bag for ordering.
Can I use the results for ordering ready‑mix delivery?
Yes, the cubic‑yard figure matches the units most suppliers use.
Do I need to include a waste factor?
Add about 10% extra to the bag count to cover breakage and spillage.
Is my data saved after I leave the page?
No, the calculation runs locally in your browser and isn’t stored.