How to use it
- Enter length, width, and thickness.
- Enter price per cubic yard.
- Click Calculate to see volume, cost, bags and cubic feet.
What it does – The calculator turns the dimensions of your slab (length, width, thickness) into four useful numbers: total cubic feet, cubic yards, estimated material cost, and how many 80‑lb bags you’ll need. Why it matters – Knowing exact volume prevents over‑ordering, saves money, and ensures you have enough mix on site. How to read the results – Cubic feet is the raw volume; divide by 27 to get cubic yards, the unit most suppliers price. Multiply cubic yards by your price per yard for cost. Divide cubic feet by 0.6 to see the bag count, rounding up to the nearest whole bag. Add a 10 % waste allowance to the bag total for cuts and spillage, then round up to the next whole bag for a safe buffer. Use the instant output to place an accurate order without guesswork.
Pro tips
- Include a 10% waste factor when ordering bags.
- Round up bag count to the next whole bag to avoid shortfalls.
- Compare supplier prices per cubic yard before finalizing cost.
- Double‑check thickness conversion (inches to feet) to prevent calculation errors.
Real-life examples
- A homeowner estimating concrete for a new patio.
- A contractor pricing a garage floor slab.
- A landscape designer planning a walkway foundation.
Case study
John needed a 12 × 15 ft patio 4 in thick. Using the calculator he saw he required 1.5 cubic yards, about 67 bags, and a $225 material cost, letting him order precisely and stay on budget.