How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches and click Calculate
What it does – Enter the length, width, and thickness of your slab and the tool instantly returns three values: total cubic feet, cubic yards, and the number of 80‑lb bags needed. Knowing cubic yards helps you order the right amount of ready‑mix, while bag count is essential for DIY mixes. The calculator uses the standard conversion that one 80‑lb bag yields 0.6 cubic feet, so you can trust the estimate. For example, a 10 ft × 10 ft slab 4 in thick equals 33.3 ft³, which is 1.23 yd³ and requires about 56 bags. Use the results to budget, avoid short‑orders, and plan waste. Read the cubic‑yard figure for truck deliveries, the bag count for store purchases, and the cubic‑feet for precise material calculations. You can also adjust the thickness to see how material needs change for different pour depths. The output is rounded up to the nearest whole bag to ensure you have enough mix on site.
Pro tips
- Add 10% extra for waste and spillage
- Round up bag count to the next whole bag
- Order ready‑mix in cubic yards for large pours
- Double‑check thickness units before calculating
Real-life examples
- A homeowner estimating bags for a DIY patio slab
- A contractor planning ready‑mix deliveries for a commercial floor
- A landscaper sizing a decorative concrete walkway
Case study
Sam needed a 12 ft × 8 ft patio 3 in thick. The calculator showed 2.0 yd³ and 67 bags, so he ordered exactly that amount, avoiding a costly over‑order and finishing on schedule.