How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic feet, cubic yards and bag count results.
This tool converts the dimensions of a block‑fill slab into three practical units: cubic feet, cubic yards and the number of 80‑lb bags of mix you’ll need. You input length, width and thickness (in inches); the calculator handles the unit conversion and division by the standard 0.6 ft³ per bag. The cubic‑feet figure tells you the raw volume, while cubic yards is the industry‑standard for ordering bulk concrete. The bag count lets you budget for ready‑mix bags if you’re doing a DIY pour. Understanding each output helps you avoid short‑orders, compare supplier quotes, and plan site logistics with confidence.
Pro tips
- Add 5‑10% extra for spillage and uneven sub‑grade.
- Round up bag totals; you can’t buy a fraction of a bag.
- Order concrete a day before the pour to keep it fresh.
- Double‑check thickness conversion from inches to feet.
Real-life examples
- A homeowner estimating material for a 4‑inch‑thick patio slab.
- A contractor pricing a block‑fill foundation for a small commercial building.
- A landscaper sizing a raised garden bed with a concrete base.
Case study
Sam entered a 12 ft × 10 ft × 4 in slab and the calculator returned 40 ft³, 1.48 yd³ and 67 bags, letting him order precisely and finish the patio on schedule.