How to use it
- Enter length in feet.
- Enter width in feet.
- Enter thickness in inches.
- Read cubic yards, bags, and cubic feet instantly.
Pour a concrete slab and you need three numbers: length, width, and thickness. Enter them in feet and inches, and this calculator returns cubic yards, total bags, and cubic feet in one click.
Why it matters: ordering too little means a mid-pour stop; ordering too much wastes money. The result tells you exactly how many 80-lb bags cover your pad, since each bag yields roughly 0.6 cubic feet. One cubic yard equals 27 cubic feet, so the math scales automatically.
Read the output as your purchase target. If the bag count is a decimal, round up — partial bags aren’t sold. The cubic yards figure helps you compare ready-mix truck quotes, while cubic feet helps visualize the volume. No subscriptions, no email, no hidden fees.
Pro tips
- Add 5–10% waste allowance for over-excavation or spillage.
- Round bag count up to the next whole bag — you can't buy partial.
- Order 10% extra if the subgrade is uneven or wet.
- Double-check thickness; a 1-inch error changes volume significantly.
Real-life examples
- Pouring a 10x10 backyard patio at 4 inches thick.
- Filling a foundation footer with known dimensions.
- Estimating bags for a garage floor before calling a truck.
Case study
A homeowner planned a 12x12 shed pad at 4 inches thick. Using the calculator, they learned they needed 36 bags instead of guessing 30. They ordered exactly the right amount, avoided a second delivery fee, and finished the pour in one day.