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.
What it does – This tool converts the dimensions of any concrete slab—length, width, and thickness—into the exact volume you’ll pour. It instantly shows the volume in cubic feet, converts that to cubic yards (the standard ordering unit), and tells you how many 80‑lb bags of mix you’ll need, using the industry‑accepted 0.6 ft³ per bag.
Why it matters – Ordering the right amount saves money and prevents project delays. Too little concrete means re‑ordering, while too much adds unnecessary cost and waste.
How to read the results – The Cubic Feet line is the raw volume. Divide by 27 to see cubic yards; the Bags line is the volume divided by 0.6, rounded up to whole bags. Use these numbers when you call your supplier.
Pro tips
- Add 5‑10% waste allowance for cuts and spillage.
- Round bag count up to the next whole bag to avoid shortfalls.
- Order bags in multiples of 5 for better pricing and handling.
- Double‑check thickness; a common mistake is entering inches as feet.
Real-life examples
- A homeowner pouring a 12 ft × 8 ft patio 4 in thick.
- A contractor estimating concrete for a 30 ft × 20 ft warehouse slab 6 in thick.
- A DIYer planning a 5 ft × 5 ft garden step 3 in thick.
Case study
Mike needed to pour a 10 ft × 15 ft driveway 5 in thick. Using the calculator he saw he required 5.6 cubic yards, which translates to 10 bags of 80‑lb mix. He ordered 10 bags, avoided a costly re‑order, and completed the job on schedule.