How to Calculate Landscape Rock, Gravel & Stone: Formula & Examples
Landscape rock, gravel, and stone are planned by volume first, then converted to weight for ordering. To calculate landscape rock for a rectangular bed, you need the length, width, and average depth of the area. This calculator converts those measurements into cubic feet, then cubic yards, and finally tons using the density of the material you choose.
Volume
cubic feet = length × width × depth in feet
cubic yards = cubic feet ÷ 27
order amount (yd³) = cubic yards × (1 + waste ÷ 100)
Weight
tons = order amount (yd³) × material density (tons per yd³)
Standard crushed stone and gravel run about 1.3–1.4 tons per cubic yard; lighter materials like decorative or lava rock run closer to 0.85 tons per cubic yard.
A 20 ft × 10 ft landscape bed with an average rock depth of 3 inches is about 1.85 cubic yards before an allowance.
With a 10% allowance, the estimate is about 2.04 cubic yards.
Using standard crushed stone (about 1.4 tons per cubic yard), that's roughly 2.85 tons to order.
How Much Landscape Rock, Gravel & Stone Do I Need? (Coverage Chart)
If you don't want to measure depth precisely, this chart gives a rough idea of how far one ton of standard gravel goes at common depths. It assumes a density of about 1.4 tons per cubic yard; lighter or heavier materials will cover a different area for the same weight.
| Depth | Coverage per ton |
|---|---|
| 1 in | ~230 sq ft |
| 2 in | ~115 sq ft |
| 3 in | ~75 sq ft |
| 4 in | ~58 sq ft |
For flower beds and ground cover, 2–3 inches is common. For walkways or heavier drainage rock, 3–4 inches or more is typical. Check your material supplier's recommendation for your specific rock type and use case.
Landscape Rock, Gravel & Stone Cost Per Unit and Price Guide
Prices vary by region, supplier, and delivery distance, but the table below gives a general sense of typical U.S. pricing by material type so you can sanity-check a quote.
| Material | Per ton | Per cubic yard |
|---|---|---|
| Crushed Stone / Gravel (standard) | $30–$75 | $35–$55 |
| 3/4" Crushed Stone | $30–$75 | $35–$55 |
| Limestone | $30–$100 | $35–$75 |
| Pea Gravel | $30–$55 | $35–$50 |
| River Rock | $45–$150 | $55–$140 |
| Decorative / Lava Rock | $75–$220 | $75–$165 |
Delivery typically adds $50–$150 or more per load depending on distance, and buying in bulk usually lowers the per-ton price. Get a quote from a local supplier for an exact number, this guide is for rough planning only.
How much rock do I need for landscaping?
The amount depends on the area you are covering and the depth you want. If you want to calculate rock for landscaping, measure each section separately when the shape is irregular and add the volumes together. Use an average depth rather than a single spot that happens to be deeper or shallower. Once you have a volume, a rock tonnage calculator step like the one above converts it into an estimated weight for ordering.
Planning your rock order
Different landscape materials have different densities, sizes, and coverage rates, which is why this rock calculator lets you pick a material before estimating tons. If your supplier sells the material by the ton or gives a coverage rate for a specific product, compare this estimate with the supplier's product information before placing the order.
Frequently asked questions
How do I calculate landscaping rock?
Measure the length and width of the area, choose an average depth, and pick the rock type you're using. This landscaping rock calculator converts the result to cubic yards, applies a waste allowance, and estimates the tonnage based on the material's density.
What depth should I use for landscape rock?
The right depth depends on the type of rock, the area, and how you want the finished surface to look. Use the depth recommended for your material rather than assuming one depth works for every project.
Should I add extra rock?
A modest allowance can help with uneven areas, measuring differences, and material left over during placement. The appropriate allowance depends on the shape and condition of the site.
Can I calculate rock for an irregular garden bed?
Yes. Divide the bed into smaller rectangles or other simple sections, calculate each section separately, and add the volumes together before converting the total to cubic yards.
How many tons of rock do I need?
It depends on your area, depth, and material. This rock calculator works it out for you: enter your measurements, pick a material, and the tonnage estimate is calculated automatically using that material's typical density.
What's the difference between 3/4 stone and regular gravel?
3/4" crushed stone refers to the size of the individual pieces, about three-quarters of an inch across. It has a similar density to standard crushed gravel, so the tonnage estimate is close, but the finished look and compaction are different, so pick the 3/4" stone option above if size matters for your project.
Is a limestone calculator different from a regular rock calculator?
Not in terms of volume, the length-width-depth formula is the same. The difference is density: limestone runs slightly lighter than standard crushed stone, which is why this calculator includes limestone as its own material option with its own tons-per-yard figure.
Does this calculator include delivery or installation cost?
No. The price guide above covers material cost only. Delivery, installation labor, and site preparation are usually quoted separately by your supplier or landscaper.