How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- Read cubic feet, cubic yards and bag count
Enter the length, width and thickness of your slab and the calculator instantly gives you three key figures: total cubic feet, total cubic yards, and how many 80‑lb bags of mix you’ll need. Knowing cubic feet helps you compare material quotes, while cubic yards is the unit most suppliers use for delivery. The bag count is derived from the fact that each 80‑lb bag yields about 0.6 ft³, so you can order the right amount without costly over‑order. The results appear in plain numbers you can copy into a purchase order or share with a contractor. You can also toggle between metric and imperial units if you prefer, and the calculator rounds up the bag count to the nearest whole bag because you can’t order a fraction of a bag. No guesswork, no hidden fees—just the exact quantities to keep your project on budget.
Pro tips
- Add 5‑10% extra for waste and spillage
- Always round bag count up to the next whole bag
- Order bags in multiples of 5 for better pricing
- Double‑check thickness; a common mistake is entering inches as feet
Real-life examples
- Homeowner pouring a 6‑ft driveway slab
- Contractor estimating concrete for a patio foundation
- DIY enthusiast planning a garden edging
Case study
Mike needed a 12 × 10 ft patio 4 in thick. Using the calculator he saw he required 40 ft³, 1.5 yd³ and 67 bags. He ordered 70 bags, avoided a second delivery, and finished on budget.