Gravel, Mulch and Topsoil Calculator
Example: Area length: 30 ft · Area width: 10 ft · Depth: 3 in · Material density: 100 lb/cu ft
| Cubic yards to order | 2.78 |
| Tons to order | 3.75 |
| Volume | 75 |
Worked example
A 30 ft by 10 ft bed filled 3 inches deep is 30 x 10 x (3/12) = 75 cubic feet, which is 75 / 27 = about 2.78 cubic yards. If it is gravel at about 100 pounds per cubic foot, that is 75 x 100 = 7,500 pounds, or 3.75 tons. Order mulch by the yard and gravel by the ton, and you will match how the yard actually sells it.
Frequently asked questions
What density should I use?
Densities vary a lot: bark mulch is roughly 20 to 30 pounds per cubic foot, topsoil around 75 to 100, and crushed gravel about 90 to 110. Use your supplier's figure if they publish one. The calculator returns both cubic yards and tons so either quoting method works.
How deep should I spread it?
Mulch is typically 2 to 3 inches for weed control without smothering roots, a gravel driveway topcoat is often 2 to 4 inches over a compacted base, and new topsoil for a lawn is commonly 4 to 6 inches. Match the depth to the job before you calculate.
Why does the answer come in both yards and tons?
Suppliers quote lightweight material like mulch by the cubic yard and heavy aggregate by the ton, because a ton of mulch is an enormous pile while a ton of gravel is compact. Having both lets you order in the unit your yard uses without a conversion error.
Should I round up when ordering?
Yes, round up to the next practical increment, since spreading always reveals thin spots and settling. Many yards sell in half-yard or quarter-ton steps. Ordering slightly over is cheaper than a second delivery fee for a small shortfall.