Rock and Decorative Stone Calculator
Calculate cubic yards, tons, and bags of decorative rock, river rock, pea gravel, or landscape stone needed for a garden bed, path, or drainage area.
Formula & Reference
| Variable | Formula | Units |
|---|---|---|
| Rock and Decorative Stone Calculator | Volume = Length x Width x Depth / 27 (cubic yards) | cubic yards + tons |
Step-by-Step Examples
15x8 ft bed, 3-inch depth, pea gravel, $55/ton.
- Area = 120 sq ft
- Volume = 120x(3/12)/27 = 1.11 cu yds
- Tons = 1.11x1.4 = 1.56 tons
- Cost = 1.56x$55 = $85.80
20x4 ft swale, 6-inch depth, river rock.
- Volume = 80x0.5/27 = 1.48 cu yds
- Tons = 1.48x1.35 = 2.0 tons
- Good for drainage channels and dry creek beds
200 sq ft garden bed, 3-inch lava rock.
- Volume = 200x0.25/27 = 1.85 cu yds
- Tons = 1.85x0.8 = 1.48 tons (lava is very light)
- Lava rock lasts indefinitely unlike organic mulch
Real-World Applications
Common Mistakes to Avoid
Decorative stone needs 2-3 inches minimum to look good and suppress weeds. At 1 inch, weeds come through quickly and stones mix with soil. Use 3-4 inches for best results and weed suppression.
Without landscape fabric beneath, stones sink into soil and weeds grow up through them within 1-2 seasons. Use non-woven geotextile fabric beneath any decorative stone application.
A cubic yard is 27 cubic feet. Many people order in yards but calculate in feet. Always verify whether your supplier quotes in yards or feet when ordering bulk deliveries.