How to use it
- Enter length in feet, width in feet, and thickness in inches.
- Click Calculate.
- Read cubic yards, bags needed, and cubic feet results.
The Concrete Soup Calculator turns the dimensions of your slab, patio, or footings into three actionable numbers: cubic yards, the standard unit for ordering, the total cubic feet, and the approximate number of 80‑lb bags you’ll need. Knowing cubic yards helps you get an accurate quote from suppliers, while bag count lets you budget material costs. The tool instantly converts your length, width, and thickness—no manual math required. After you hit Calculate, the results appear in a clear table. Use the cubic‑yard figure for delivery orders, the bag count for purchasing, and the cubic‑foot total to compare different mix designs. All results are based on the industry‑standard 0.6 ft³ per 80‑lb bag, so you can trust the estimate. If you’re working with a sloped surface, measure the average thickness for the most accurate estimate. The calculator also shows the result in cubic yards rounded to two decimals for easy ordering.
Pro tips
- Add 5‑10% extra for waste and spillage.
- Round up bag count to the next whole bag to avoid shortfalls.
- Order concrete a day early to ensure delivery availability.
- Double‑check thickness conversion from inches to feet before calculating.
Real-life examples
- Estimating material for a new 10 ft × 15 ft driveway slab.
- Planning the concrete needed for a backyard patio with varying thicknesses.
- Sizing the mix for a small foundation wall before ordering delivery.
Case study
John needed a 12×12‑ft patio 4 in thick. Using the calculator he saw he required 1.78 yd³, about 30 bags, and ordered exactly that, avoiding a $150 over‑order.