Work out how many cubic yards and tons of rock, gravel or decomposed granite you need, and estimate what a boulder weighs before you try to move it.
Get a Free Rockscape EstimateTo figure how much rock you need, multiply the area in square feet by the depth in inches, divide by 12 to get cubic feet, then divide by 27 to get cubic yards. Multiply cubic yards by about 1.3 to 1.5 to get tons, since most landscape rock and decomposed granite weigh in that range per cubic yard. The calculator below does the math for one area or several.
The weights come from published supplier figures (Earth Stone Rock), so treat the result as a solid estimate, not a delivery ticket. Rock weight changes with moisture and size. Ask your yard whether it sells by the ton or the yard before you order. If you are still picking a material, start with our landscape rock types guide or the rock and DG hub.
Add each bed, path or side yard as its own area. Use feet for size and inches for depth. Odd shapes work fine if you break them into rectangles, circles and triangles.
Rock weight varies with moisture and size, so treat tons as a range of about 1.3 to 1.5 tons per cubic yard. Most yards sell by the ton or the yard; ask which.
One cubic yard is 27 cubic feet. That means one cubic yard spread 1 inch deep covers 324 square feet, 2 inches deep covers 162, 3 inches covers 108 and 4 inches covers 81 (Earth Stone Rock rounds these to 300, 150, 100 and 80).
Handy when the yard quotes by the ton. Figures are calculated from the cubic yard math above at two common weights.
| Depth | At 1.35 tons per cu yd | At 1.5 tons per cu yd |
|---|---|---|
| 1 inch | about 240 sq ft per ton | about 216 sq ft per ton |
| 2 inches | about 120 sq ft per ton | about 108 sq ft per ton |
| 3 inches | about 80 sq ft per ton | about 72 sq ft per ton |
| 4 inches | about 60 sq ft per ton | about 54 sq ft per ton |
Stabilized DG is figured differently. One manufacturer’s spec says one ton covers about 65 square feet at 3 inches compacted (Stabilizer Solutions), which is why the calculator treats it as its own option. More on that in our stabilized DG guide.
| Material | Working weight | Source |
|---|---|---|
| Decomposed granite | about 1.35 tons (2,700 lb) per cu yd | Earth Stone, Yard Compass |
| Crushed rock and landscape gravel | about 1.35 tons per cu yd | Earth Stone |
| Decorative landscape rock | about 1.4 tons per cu yd | Earth Stone |
| River rock | about 1.45 tons per cu yd | Earth Stone |
| Solid granite (not crushed) | about 2.27 tons per cu yd | Stone Calculator |
Why is crushed rock so much lighter than solid stone? Roughly a third of a crushed pile is air between the pieces (Stone Calculator). Wet rock weighs more than dry rock, so a load after rain can come in heavier.
| Use | Typical depth | Notes |
|---|---|---|
| Decorative rock beds around plants | 2 to 3 inches | Mojave Water Agency recommends a 2 to 3 inch mulch layer, and rock counts (MWA). Majestic Rock & Material puts most beds at 2 to 3 inches (Majestic). |
| Stabilized DG path, light foot traffic | 3 inches compacted | Over a compacted base (Stabilizer Solutions). |
| Stabilized DG, heavy foot traffic | 4 inches compacted | Placed in two 2 inch lifts (Stabilizer Solutions). |
| Larger rock and cobble (1.5 inch and up) | Ask your installer | We did not find a published standard. Bigger stone usually needs enough depth to hide the fabric or soil between pieces. |
Building a path? Our DG pathway how-to covers base, edging and lifts.
Measure the boulder at its longest, widest and tallest points. The calculator multiplies the box size by a shape factor and the density of the stone. Granite runs about 168 pounds per cubic foot, sandstone about 140 and limestone about 160 (Stone Calculator).
Estimate only. Boulders have voids, cracks and odd shapes, so real weights can run lighter or heavier. Anything over about 170 lb is past what two people should carry.
For a chart of common sizes and tips on placing them, see our landscape boulders guide.
Victorville averages about 97°F in July and gets most of its wind in spring, with April the windiest month (Weather Spark). Two things to plan for out here:
Want it done for you? Professionally installed rockscape runs about $3 to $6 per square foot in our area, including base work and edging. See our rockscape service, Hesperia rockscape or Victorville rockscape pages, or browse cost guides.
At 2 inches deep, one ton of gravel or decomposed granite covers roughly 108 to 120 square feet, depending on whether it weighs 1.5 or 1.35 tons per cubic yard. At 3 inches deep it covers about 72 to 80 square feet.
Most landscape rock and decomposed granite weigh about 1.3 to 1.5 tons per cubic yard. Earth Stone Rock uses about 1.35 tons for DG and crushed rock, 1.4 for landscape rock and 1.45 for river rock. Wet rock weighs more.
A 10 by 10 foot area is 100 square feet. At 2 inches deep that is about 0.6 cubic yards, or a little under a ton. At 3 inches deep it is about 0.9 cubic yards, or roughly 1.3 tons at 1.4 tons per yard.
Two to 3 inches is typical for decorative rock beds, and Mojave Water Agency recommends a 2 to 3 inch mulch layer that can be rock. Stabilized DG paths go 3 inches compacted for light traffic and 4 inches for heavy traffic.
Measure its length, width and height in inches, multiply them, divide by 1,728 to get cubic feet, then multiply by a shape factor of about 0.5 to 0.8 and by the stone's density, about 168 pounds per cubic foot for granite. The boulder calculator on this page does it for you.
We checked every number on this page against the public sources below. If a rule or date changes, the agency page is the final word.
We design and install rockscape and DG across the High Desert and Inland Empire, base work and edging included. Free on-site estimate, honest number.
Get a Free Rockscape EstimateOr call (760) 792-7627
