How to use it
- Enter length in feet, width in feet, and thickness in inches.
- Click the Calculate button.
- Read the cubic yards, cubic feet and bag count results.
Enter the length, width and slab thickness, and the calculator instantly gives you the total concrete volume in cubic feet, converts it to cubic yards and tells you how many 80‑lb Quikrete bags you’ll need. Knowing the exact volume prevents ordering too little, which can delay a project, or too much, which wastes money. The cubic‑yard figure is useful for contractors who price by the yard, while the bag count helps DIY homeowners buy the right number of bags from the store. Results are shown with two decimal places so you can see precise amounts and make informed ordering decisions. One cubic yard equals 27 cubic feet, so the tool divides the cubic‑foot total by 27 to give you yards. Then it divides the cubic‑foot total by 0.6, the yield of a standard 80‑lb bag, to calculate the bag count. The numbers are rounded up because you can’t purchase a fraction of a bag.
Pro tips
- Add 5‑10% extra for waste or spillage
- Round up the bag total; you can’t buy a partial bag
- Order a full pallet if you need many bags to save on delivery
- Double‑check thickness conversion from inches to feet before entering
Real-life examples
- Pouring a 4×8 foot patio slab 4 inches thick
- Installing a concrete driveway strip 2 feet wide and 6 inches deep
- Repairing a small foundation crack with a 1×3 foot patch 3 inches thick
Case study
Sam entered his 10 × 12 ft patio dimensions and 4‑inch thickness. The calculator showed 0.58 cubic yards, which translated to 11 bags. He ordered 12 bags, avoided a costly shortfall, and completed the patio on schedule.