How to use it
- Enter length, width and thickness in the fields.
- Click the Calculate button.
- Read the cubic feet, cubic yards and bag count results.
What it does Enter the length, width and thickness of your slab and the calculator instantly returns three values: total cubic feet, cubic yards, and the number of 80‑lb bags required.
Why it matters Knowing cubic yards helps you order the right amount of ready‑mix concrete, while bag count is essential for DIY mixes. Accurate estimates prevent costly over‑orders and avoid running short mid‑project.
How to read the results
- Cubic feet – raw volume before conversion.
- Cubic yards – divide cubic feet by 27; this is the unit most suppliers quote.
- Bags – divide cubic feet by 0.6 (each bag yields 0.6 ft³). Round up to the nearest whole bag.
Use the numbers to compare quotes, plan delivery dates, and keep your budget on track.
Pro tips
- Add 5‑10% waste to the total volume for cuts and spillage.
- Always round bag count up to the next whole bag.
- Order a little extra if delivery windows are limited.
- Double‑check thickness conversions from inches to feet before entering.
Real-life examples
- A homeowner estimating material for a new 12 ft × 24 ft patio slab.
- A contractor pricing a 10 ft × 30 ft driveway with a 4‑inch thickness.
- A DIY enthusiast planning a raised garden bed that’s 8 ft × 6 ft × 6 in.
Case study
Mike needed a 12 × 20 ft patio 4 in thick. Using the calculator, he saw he required 2.1 cubic yards, which translated to 118 bags. He ordered 120 bags, avoided a second delivery, and finished on budget.