20×10 ft bed at 3 in
Input
20 ft × 10 ft × 3 inOutput
50 cu ft · 1.85 cu yd20 × 10 × 3 ÷ 324 = 1.85 cu yd.
Landscape rock volume is **area × depth**. For US beds and tree rings, measure length and width in feet and depth in inches.
**Imperial formula (rectangle):**
Cubic yards = Length (ft) × Width (ft) × Depth (in) ÷ **324**
**Example — 20×10 ft bed, 3 in river rock:**
20 × 10 × 3 ÷ 324 = **1.85 cubic yards** (50 cu ft)
**Tree ring (circle):**
Volume = π × (radius ft)² × depth (ft)
**Example — 8 ft diameter ring, 3 in deep:**
π × 4² × 0.25 = **12.6 cu ft** (~0.47 cu yd)
**Coverage shortcut:** At 3 in depth, **1 cubic yard covers ~108 sq ft**. At 2 in accent topping, one yard covers ~162 sq ft.
**Metric formula:**
Volume (m³) = Area (m²) × Depth (cm) ÷ 100
Decorative rock is sold **bulk by the cubic yard** or in **bagged cubic feet** at retail. Add **5–15% extra** for spillage, irregular beds, and wheelbarrow loss.
The calculator treats the rocked zone as a flat rectangular prism, total area × depth, or cylinder for tree rings. An optional buffer increases order quantity for spillage and uneven beds.
Formula
cu yd = L(ft) × W(ft) × D(in) ÷ 324 | circle: π × r² × D(ft) ÷ 27 | m³ = area(m²) × D(cm) ÷ 100Tap Accent topping (2 in), Landscape bed (3 in), Dry creek (4 in), or Tree ring — each sets recommended depth. Use bed presets for common rectangle and circle sizes.
Enter length × width for rectangular beds, total square footage for irregular zones, or diameter for tree rings. Measure the rocked area only — not lawn or paths.
Tap depth presets: 2 in for thin accent over fabric, 3 in for standard bed cover, 4 in for dry creek average depth. Avoid piling rock against tree trunks.
Bulk suppliers quote by the cubic yard. Results show ton estimates by stone type when suppliers bill by weight instead of volume.
Enable the buffer for irregular beds and spillage. Enter bag size (0.5 cu ft is common at retail) for bag count — bulk delivery is usually cheaper above ~2 cu yd.
Input
20 ft × 10 ft × 3 inOutput
50 cu ft · 1.85 cu yd20 × 10 × 3 ÷ 324 = 1.85 cu yd.
Input
⌀ 8 ft × 3 inOutput
12.6 cu ft · 0.47 cu ydπ × (4 ft)² × 0.25 ft = 12.57 cu ft.
Input
200 sq ft × 2 inOutput
33.3 cu ft · 1.23 cu ydThin accent layer over landscape fabric.
Input
25 m² × 7 cmOutput
1.75 m³ · 1,750 L25 × 0.07 m depth = 1.75 cubic meters.
Common real-world scenarios where this tool saves time.
20×10 ft bed at 3 in river rock: 200 × 3 ÷ 12 = 50 cu ft → ~1.85 cu yd. Order 2 yards with buffer. Install edging and fabric before spreading stone.
8 ft diameter ring at 3 in: ~12.6 cu ft (~0.47 cu yd). Keep rock 2–4 in from trunk bark. Use circle mode for accurate volume.
40 ft creek averaging 3 ft wide at 4 in depth: ~120 sq ft × 4 in ÷ 12 = 40 cu ft → ~1.48 cu yd. Variable depth creeks — measure average width and depth.
25 m² bed at 7 cm: 25 × 0.07 = 1.75 m³. Useful when EU suppliers quote bulk bags in litres or tonnes.
Step-by-step chains that connect related tools for common tasks.
From measurement to delivery in four steps.
Coordinate hardscape materials.
| Depth | Sq ft per cu yd | Typical use |
|---|---|---|
| 2 in | 162 | Accent topping over fabric |
| 3 in | 108 | Standard landscape bed |
| 4 in | 81 | Dry creek average depth |
Formula: 324 ÷ depth (inches) = sq ft per cubic yard.
| Factor | Landscape rock | Mulch |
|---|---|---|
| Weed suppression | Good with fabric | Good at 3 in depth |
| Soil improvement | None — inert | Adds organic matter |
| Heat retention | Higher — radiates heat | Moderate |
| Refresh cycle | Years — occasional top-up | Annual top-dress |
Fabric under rock blocks most weeds. Without it, stone mixes into soil and is hard to refresh later.
Keep decorative stone **2–4 in from bark**. Moisture trapped against trunks causes rot — same risk as volcano mulch.
Round decorative rock shifts under tires. Driveways need **crushed angular stone** — use the Gravel Calculator instead.
River rock is less dense than limestone. Ask your supplier for **tons per cubic yard** for your specific stone.
Measure the **bed footprint** only — the zone you will actually cover with rock.
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At 3 in depth, 10×10 ft = 100 sq ft. Volume = 100 × 3 ÷ 12 = 25 cu ft, or about 0.93 cubic yards. Round up to 1 yard for bulk or check bag count at retail.
2 in for accent topping over fabric, 3 in for standard bed cover, 4 in average for dry creek beds. Avoid depths over 4 in in planting beds — roots need soil contact.
Divide 324 by depth in inches. At 3 in, one yard covers 108 sq ft. At 2 in, 162 sq ft. At 4 in, 81 sq ft.
Depends on stone type. River rock and lava rock are lighter (~1.0–1.3 tons/yd³); limestone and granite heavier (~1.4–1.6 tons/yd³). Confirm with your supplier.
Under ~1 cubic yard, bags are simpler. Above 2–3 cubic yards, bulk delivery usually costs less per cubic foot if you can receive a truck dump.
Yes for most beds. Fabric blocks weeds and keeps stone from sinking into soil. Cut X-slits for existing plants rather than piling rock against trunks.
Use Tree ring (⌀) mode. An 8 ft ring at 3 in needs about 12.6 cu ft (0.47 cu yd). Keep rock away from the trunk bark.
Landscape rock usually means decorative river rock, pea gravel, or lava stone for beds. Gravel often means crushed angular stone for paths and structural bases — see the Gravel Calculator for paths and driveways.
Bed dimensions and depth values are processed only in your browser — EverydayTools does not collect or store your measurements.
Volume estimates only — not landscape contracting or structural engineering. Confirm order quantities with your supplier.
Part of Calculator Tools
More free tools for the same workflow.
Free mulch calculator: enter bed size or square footage and depth → cubic yards, cubic feet, liters, and bag counts. Depth presets, coverage tables, optional buffer. Imperial or metric. Runs locally in your browser.
Free gravel calculator: path, patio, or driveway footprint and depth → cubic yards, ton estimates, cubic feet, liters, and bag counts. Use-case depth guide, round pad mode, compaction buffer. Runs locally in your browser.
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Reviewed on 2026-06-28.
Rock use case
3 in — standard river rock or pea gravel cover.
Rock depth presets
2 in accent topping; 3 in standard bed cover; 4 in dry creek average depth.
Bagged decorative rock — often 0.5 cu ft at retail. Leave blank to skip bag count.
1 cubic yard covers
| Depth | Sq ft |
|---|---|
| 1 in | 324 |
| 2 in | 162 |
| 3 in | 108 |
| 4 in | 81 |
Bag coverage at 3 in depth
| Bag | Covers | Per cu yd |
|---|---|---|
| 1 cu ft bag | 4 sq ft | 27 bags |
| 1.5 cu ft (40 L) | 6 sq ft | 18 bags |
| 2 cu ft bag | 8 sq ft | 14 bags |
| 3 cu ft bag | 12 sq ft | 9 bags |