How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic yards, bags and cubic feet results.
What it does – The 1 1 2 Concrete Mix Calculator turns the three dimensions you enter (length, width, thickness) into three practical outputs: total cubic yards of concrete, the number of 80‑lb bags you’ll need, and the raw cubic‑feet volume. Knowing the exact cubic yards helps you order the right amount of ready‑mix from a supplier, while the bag count tells you how many pre‑mixed bags to buy for small jobs. The cubic‑feet figure is useful for comparing against material specs or for on‑site calculations. The results appear instantly, so you can adjust dimensions, add a waste factor, or experiment with different slab sizes without guessing. All you need is the size of the area you’re pouring; the calculator does the rest.
Pro tips
- Add 5‑10% extra for spillage and uneven sub‑grade.
- Round up bag count to the nearest whole bag to avoid shortages.
- Order bags in multiples of 10 for easier delivery and pricing.
- Double‑check thickness conversion (inches to feet) before entering.
Real-life examples
- A homeowner estimating concrete for a new driveway slab.
- A contractor sizing a concrete pad for a shed foundation.
- A DIY enthusiast planning a garden walkway with varying widths.
Case study
John needed a 12‑ft by 12‑ft patio 5 in thick. Using the calculator he saw he required 1.33 cubic yards, about 74 bags. He ordered 75 bags, avoided a costly short‑fall, and completed the patio on schedule.