Rock Calculator
Estimate tons, cubic yards, and bags of landscaping rock
Surface area to cover with rock
Desired rock depth (2" is typical)
Affects weight and appearance
Cubic Yards
—
cu yd
Bags (0.5 cu ft)
—
bags
Tons
—
tons
Disclaimer: Results are estimates based on standard formulas. Not a substitute for professional advice from a licensed contractor, engineer, or architect. Verify all calculations before making purchasing or construction decisions.
How to Use This Calculator
Adding decorative rock to your yard? Accurate material estimates keep your budget on track and prevent mid-project supply runs. Our calculator converts area and depth into tons, cubic yards, and bags.
- Measure the length and width of the area to cover
- Decide on rock depth — 2" for decorative, 3-4" for pathways
- Enter the area and depth into the calculator
- Choose your rock type and add 5-10% for waste and settling
Expert Insights
Smart analysis for your Rock project
Weight Density Smarts
River rock, crushed stone, and pea gravel each weigh slightly different per cubic yard. Our AI uses the standard 1.4 tons/cu yd conversion that fits most decorative stone.
Weed Barrier Recommendation
Always lay landscape fabric under decorative rock. A 2" layer over fabric suppresses weeds for years, while bare soil lets weeds push through within a season.
Bulk vs Bag Decision
Bagged rock costs 3-5x more per ton than bulk delivery. For projects over 2 cubic yards, order bulk delivery — it saves money and countless trips to the store.
Calculation Formula
Cubic yards = (Area × Depth) / 324
Tons = Cubic yards × 1.4 (rounded up to 0.1)
Bags = Cubic yards × 54 (0.5 cu ft bags, rounded up)
Rock Material Comparison
| Rock Type | Typical Size | Best Use | Cost per Ton | Weight (tons/cu yd) |
|---|---|---|---|---|
| River Rock | 1-3 inches | Decorative beds, dry creeks | $130-200 | 1.4 |
| Crushed Stone | 3/4 inch | Driveways, base layer | $45-100 | 1.4 |
| Pea Gravel | 3/8 inch | Pathways, play areas | $40-80 | 1.4 |
Authority References
Our calculations are based on guidelines and standards from these authoritative sources:
- National Association of Landscape Professionals (NALP) — Landscape Installation Best Practices. Learn more
- American Society of Civil Engineers (ASCE) — Standards for Aggregate Materials and Testing. Learn more
- American Association of State Highway and Transportation Officials (AASHTO) — Aggregate Specification Standards. Learn more
Frequently Asked Questions
How do I calculate how much rock I need?
Multiply your area in square feet by the depth in inches, then divide by 324 to get cubic yards. Multiply cubic yards by 1.4 to convert to tons for most landscaping rock.
How deep should landscaping rock be?
A 2-inch depth is standard for decorative rock over weed barrier. Use 3-4 inches for high-traffic pathways or driveways to prevent bare spots.
How many bags of rock equal a cubic yard?
A 0.5 cubic foot bag holds about 54 bags per cubic yard. Bulk delivery by the ton is far cheaper for projects over 2 cubic yards.