How to use it
- Enter length in feet, width in feet, and depth in inches.
- Click the calculate button to see cubic yards, tons and cubic feet.
- Adjust dimensions or add waste factor and recalculate as needed.
Enter the length, width and depth of the area you plan to fill with drain rock. The tool first turns the dimensions into cubic feet, then groups them into cubic yards (27 ft³ per yard). Because each cubic yard of rock weighs about 1.4 US tons, the calculator also shows an approximate tonnage. Knowing cubic yards helps you order the right volume from suppliers, while the ton estimate lets you compare pricing that’s often listed by weight. The results appear instantly, so you can adjust dimensions, add a waste factor, or compare multiple projects without manual math. You can also switch between metric and imperial units if your supplier uses different measurements. The calculator stores your last entry, making it easy to revisit a project later.
Pro tips
- Add 5‑10% extra volume for breakage and spillage
- Round up to the nearest whole cubic yard to avoid shortfalls
- Order by weight if the supplier quotes per ton
- Double‑check depth conversion from inches to feet
Real-life examples
- Homeowner installing a French drain in the backyard
- Contractor estimating material for a driveway trench
- Landscaper planning a garden bed drainage system
Case study
Mike needed to fill a 12 ft × 8 ft trench 6 in deep for drainage. Using the calculator he saw he required 1.8 cubic yards (≈2.5 tons). He ordered exactly that amount, saved $150 on excess rock, and completed the job on schedule.