How to use it
- Enter the length in feet.
- Enter the width in feet.
- Enter the thickness in inches.
- Read the cubic yards, cubic feet and bag count results.
How it works
The calculator turns the three dimensions you provide—length, width and thickness—into the three most useful units for ordering concrete: cubic yards, cubic feet, and the number of 80‑lb bags needed. Knowing the exact volume helps you avoid over‑ordering, which saves money, and under‑ordering, which can delay the job.
- Cubic yards are the standard delivery unit for contractors.
- Cubic feet gives a finer view of the space you’ll fill.
- Bags tells you how many 80‑lb mixes to purchase; each bag equals about 0.6 cubic ft.
Read the three numbers, round as needed, and place your order with confidence.
Pro tips
- Add a 5‑10% waste allowance for cuts and spillage.
- Round up the bag count to the nearest whole bag; you can’t buy a fraction of a bag.
- Order a little extra if you’re unsure about the exact thickness on uneven ground.
- Double‑check that thickness is entered in inches, not feet, to avoid large errors.
Real-life examples
- A homeowner pouring a 4‑ft‑by‑6‑ft patio 4 in thick wants to know how many bags to buy.
- A contractor estimating concrete for a 12‑ft‑wide driveway 6 in deep needs cubic yards for the supplier quote.
- A DIYer building a raised garden bed 2 ft long, 1 ft wide, and 8 in thick wants to compare bag costs versus ready‑mix delivery.
Case study
Mike needed concrete for a 5 × 8 ft patio 4 in thick. Using the calculator he saw he required 1.5 cubic yards, which translates to 12 bags (0.6 ft³ per bag). He ordered exactly that amount, saved $45 on excess material, and completed the patio on schedule.