Rock Calculator
Calculate landscape rock coverage from tons, cubic yards, bed size, and depth.
Rock Coverage
Depth preset
Ready to calculate
Enter a rock amount, depth, and material type.
Last updated May 29, 2026 by our expert review team
Quick Coverage Table
Use this as a fast reality check. The ton column assumes a 100 lb per cu ft mid-weight decorative rock.
| Depth | 1 ton covers | 1 cu yd covers | Good for |
|---|---|---|---|
| 2 in | 120 sq ft | 162 sq ft | thin decorative cover |
| 3 in | 80 sq ft | 108 sq ft | garden beds and weed cover |
| 4 in | 60 sq ft | 81 sq ft | larger stone and shrub beds |
| 6 in | 40 sq ft | 54 sq ft | drainage edges and heavier layers |
Expert Contributors
Ruth Wairimu
Landscape Architect
Landscape architect with 9+ years of experience, AAK member, IFLA climate activist, and founder of Bloomwell.
See full profileHawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated May 2026
How we verify our calculatorsWhat Will Your Rock Cost?
Set your bed once, then switch between the bags-vs-bulk decision and a cost comparison across rock types.
$450
75 bags · 0.5 cu ft each
$217
1.9 tons + $90 delivery
Bulk wins: ~$217 vs ~$450 in bags — you save about $233 after a ~$90 delivery.
That's ~1.9 tons ≈ 4 pickup loads — most projects this size get bulk delivered.
Rough estimate (bags ~$6 each; bulk at the type's average $/ton + delivery). Local prices and minimums vary.
Depth Changes Coverage
The same pile of rock spreads farther when the layer is shallow. Choose depth first, then compare tons or cubic yards.
Same material, different depth. A 4 inch layer covers about half the area of a 2 inch layer.
Rock Size & Coverage
Smaller stone packs tighter and covers more area per ton; larger stone covers less but resists washout and shifting. Coverage shown at about 2 inches deep — bigger stone usually goes deeper.
| Rock size | Coverage / ton |
|---|---|
| Pea / under 1 in | ~120 sq ft |
| Small ~1 in | ~110 sq ft |
| Medium 1–3 in | ~90 sq ft |
| Large 3–5 in | ~70 sq ft |
| Cobble 5–8 in | ~55 sq ft |
Coverage at ~2 in deep; larger stone is usually laid 3–4 in deep, lowering coverage per ton further.
Pro Tips
Depth changes coverage more than most people expect. Going from 2 inches to 4 inches cuts the covered area in half.
Use the ton-to-area mode when a supplier quote says one ton, one cubic yard, or one bulk bag. It answers the fast shopping question.
Round up for curved beds, exposed edges, and hand-spread projects. A 10 percent cushion is usually enough for simple shapes.
For material-specific estimates, compare the Stone Calculator, River Rock Calculator, and Pea Gravel Calculator.
For compacted base layers, use the Crusher Run Calculator or Crushed Stone Calculator instead.
How This Calculator Works
Rock coverage is a volume problem. Multiply the area by depth to get cubic feet, then convert to cubic yards or tons.
Weight depends on density. Lava rock is light, rounded river rock is usually mid-weight, and compact crushed stone can be heavier by the cubic yard.
Core formulas
Area covered = cubic feet of rock / depth in feet
Tons = cubic feet x density / 2,000
Cubic yards = cubic feet / 27
Supplier sells by the yard
Use cubic yards for the cleanest coverage check. Volume does not depend on rock density.
Supplier sells by the ton
Pick the closest rock type. Lightweight lava rock and dense crushed stone cover very different areas.
Depth Notes
- Small stone
- 2 in
- 3/4 to 1 in stone
- 3 in
- Larger rock
- 4 in
- Drainage edge
- 4 to 6 in
Common Rock Coverage Examples
One-ton garden refresh
1 ton at 2 in
about 120 sq ft
Good for a thin decorative top-up.
Typical bed depth
1 ton at 3 in
about 80 sq ft
A common choice around shrubs and paths.
Bulk cubic yard
1 cu yd at 4 in
about 81 sq ft
Useful when the supplier sells by the yard.
Rock Coverage FAQ
How many square feet does 1 ton of rock cover?
For a mid-weight decorative rock, about 120 sq ft at 2 inches, 80 sq ft at 3 inches, or 60 sq ft at 4 inches.
How many square feet does 1 cubic yard cover?
Pure volume gives about 162 sq ft at 2 inches, 108 sq ft at 3 inches, and 81 sq ft at 4 inches.
Why do supplier charts vary?
Rock size, moisture, void space, and density change the ton-to-area conversion. Cubic-yard coverage is more stable because it is volume-based.
Should I buy bags or bulk rock?
Bags work for small accents and repairs. Bulk usually makes more sense once the project is more than a few dozen square feet.
What if my area is curved?
Break it into rectangles, calculate each area, then add 10 to 15 percent for curves, edges, and hand spreading.
Can I use this for compacted base stone?
Use the Crusher Run Calculator or Crushed Stone Calculator for compacted base projects.
Important Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.