How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic feet, cubic yards and bag count.
Your concrete slab project starts with the right numbers. This calculator turns the length, width and thickness you input into three practical results: total cubic feet of concrete, the equivalent cubic yards for ordering, and the number of 80‑lb bags needed (each bag = 0.6 ft³). Knowing cubic feet helps you compare contractor quotes, while cubic yards is the unit most suppliers use. The bag count tells you exactly how many mixes to buy, avoiding costly over‑orders. Simply plug your dimensions, hit calculate, and you’ll see a clear, instant summary you can copy into your purchase list or project plan. You can also round up to the nearest whole bag to ensure you have a small margin, and the tool instantly converts the volume to yards so you can give suppliers the exact figure they require.
Pro tips
- Add 5‑10% extra for waste and spillage.
- Round bag count up to the next whole bag.
- Order concrete in cubic yards; suppliers price by the yard.
- Double‑check thickness conversion from inches to feet.
Real-life examples
- Homeowner estimating concrete for a 12 ft × 12 ft patio.
- Contractor pricing a 24 ft × 48 ft warehouse floor.
- DIY gardener planning a 6 ft × 8 ft shed foundation.
Case study
Mike needed a 10 ft × 20 ft driveway 4 in thick. Using the calculator he saw the job required 59 cubic ft, about 2 cubic yds and 98 bags. He ordered 100 bags, saved $200 by avoiding over‑order, and the project stayed on schedule.