Rock Calculator
Calculate rock volume, weight, and optional cost using multiple shapes and material density inputs. Also works as a stone calculator or gravel calculator.
Quick Answers
- A ton of rock covers about 100 to 120 square feet at a standard 2-inch depth (varies by rock type; lava rock covers roughly double).
- A cubic yard of rock weighs about 1.35 tons (2,700 lbs) for standard gravel, crushed granite, or decomposed granite. River rock runs slightly heavier at 1.4 tons; lava rock is much lighter at 0.75 tons.
- A cubic yard of rock costs $50 to $150 delivered, depending on rock type and distance from the quarry.
- A ton of rock costs $35 to $120 for material, plus $50 to $200 for delivery if it's not included.
- 1 cubic yard covers about 108 square feet at 3 inches deep, or about 162 square feet at 2 inches deep.
How to Use the Rock Calculator (Stone Calculator)
Enter 4 values to calculate your rock order: the length and width of the coverage area in feet, the desired depth in inches, and the type of rock. The calculator returns cubic yards, tons, and an estimated cost range for your area.
- Enter area dimensions: length and width in feet; for irregular shapes, break the area into rectangles and add totals
- Select rock depth: 2 to 3 inches for decorative coverage, 4 to 6 inches for weed suppression, 6 to 12 inches for drainage or base layers
- Choose rock type: each rock type has a different weight per cubic yard (lava rock is lighter; river rock and crushed granite are heavier)
- Review tons and cubic yards: use tons when buying from bulk suppliers; use cubic yards for delivery truck estimates
- Add delivery and labor: most bulk rock suppliers charge by the ton delivered; installation adds $50 to $100 per ton for spreading
Rock Size Chart: What Size Rock Do I Need?
Rock and gravel are sold by particle size as well as by type. Quarries and suppliers label sizes using standard grade numbers or common names, and picking the right size matters as much as picking the right rock type: a size that's too small won't stay in place on a slope, and a size that's too large won't compact for a base layer. Use the chart below to match rock size to your project.
| Size Name | Diameter Range | Also Called | Best Use |
|---|---|---|---|
| Stone Dust / Screenings | Under 1/8" | Fines, #10 | Paver base binder, filling joints |
| Pea Gravel | 1/8" – 3/8" | #8, pea stone | Walkways, garden beds, playgrounds, aquariums |
| Crushed Stone (small) | 3/8" – 3/4" | #57, road base | Driveways, drainage, concrete mix |
| Crushed Stone (medium) | 3/4" – 1.5" | #4 | French drains, larger drainage runs |
| River Rock (decorative) | 1" – 3" | Round rock, Mexican beach pebble | Decorative beds, dry creek beds, borders |
| Cobblestone | 3" – 10" | Cobble | Accent borders, retaining wall facing |
| Riprap (small) | 4" – 8" | Rock riprap, class 1 | Light erosion control, slope stabilization |
| Riprap (large) | 8" – 24"+ | Boulder riprap, class 2–4 | Heavy erosion control, embankments, shoreline |
Rule of thumb
The smaller the rock, the more finished and walkable the surface, but the more it migrates over time and needs edging to contain it. The larger the rock, the more permanent and erosion-resistant it is, but it's not suitable for anywhere people walk barefoot or a mower needs to pass.
Rock Types, Weight, and Coverage: 2026 US Averages
Different rock types have significantly different densities. Choosing the wrong type when estimating results in under-ordering (project delays) or over-ordering (wasted cost). Use the table below to select the correct density for your material.
| Rock Type | Lbs per Cu Yd | Tons per Cu Yd | Cu Yds per Ton | Best Use |
|---|---|---|---|---|
| Decomposed Granite | 2,700 lbs | 1.35 tons | 0.74 cu yd | Pathways, driveways |
| Crushed Limestone | 2,565 lbs | 1.28 tons | 0.78 cu yd | Base layers, drainage |
| River Rock (pea gravel) | 2,800 lbs | 1.40 tons | 0.71 cu yd | Garden beds, borders |
| Crushed Granite | 2,700 lbs | 1.35 tons | 0.74 cu yd | Pathways, compactable base |
| Lava Rock | 1,500 lbs | 0.75 tons | 1.33 cu yd | Decorative, mulch replacement |
| Marble Chips | 2,565 lbs | 1.28 tons | 0.78 cu yd | Decorative garden beds |
| Crushed Concrete | 2,025 lbs | 1.01 tons | 0.99 cu yd | Base fill, driveway sub-base |
| White Marble Gravel | 2,430 lbs | 1.22 tons | 0.82 cu yd | Decorative, high-contrast beds |
Rock Coverage by Depth: Square Feet per Ton
Coverage varies significantly by depth. A 2-inch depth is adequate for decorative groundcover and weed suppression in established beds. Drainage applications and high-traffic paths typically require 4 to 6 inches of compacted rock.
| Rock Type | 1 Inch Deep | 2 Inches Deep | 3 Inches Deep | 4 Inches Deep |
|---|---|---|---|---|
| River Rock / Pea Gravel (2,800 lbs/cu yd) | 231 sq ft/ton | 116 sq ft/ton | 77 sq ft/ton | 58 sq ft/ton |
| Decomposed Granite / Crushed Granite (2,700 lbs/cu yd) | 240 sq ft/ton | 120 sq ft/ton | 80 sq ft/ton | 60 sq ft/ton |
| Crushed Limestone / Marble Chips (2,565 lbs/cu yd) | 253 sq ft/ton | 126 sq ft/ton | 84 sq ft/ton | 63 sq ft/ton |
| Lava Rock (1,500 lbs/cu yd) | 432 sq ft/ton | 216 sq ft/ton | 144 sq ft/ton | 108 sq ft/ton |
River Rock/Pea Gravel is shown separately from Decomposed Granite since the two have different densities (2,800 vs. 2,700 lbs/cu yd), so their coverage per ton isn't identical.
Rock Landscaping Cost by Project Type: 2026
Costs below include material and standard delivery within 20 miles. Installation (spreading, grading, and edging) adds $50 to $100 per ton or $2 to $4 per square foot, depending on site access and slope.
| Project Type | Typical Area | Depth | Tons Needed | Estimated Cost |
|---|---|---|---|---|
| Small garden bed | 100 sq ft | 2 in | 0.6 – 0.8 tons | $50 – $120 |
| Medium garden beds | 300 sq ft | 2 in | 1.8 – 2.2 tons | $150 – $280 |
| Full front yard | 1,000 sq ft | 3 in | 6.5 – 8.0 tons | $400 – $900 |
| Gravel driveway (base) | 1,800 sq ft | 6 in | 20 – 26 tons | $800 – $2,200 |
| Backyard drainage trench | 150 linear ft | 12" wide/deep | 8 – 12 tons | $350 – $900 |
| Playground border | 500 sq ft | 6 in | 9 – 12 tons | $500 – $1,100 |
| Commercial parking lot base | 5,000 sq ft | 6 in | 55 – 70 tons | $2,200 – $6,000 |
Full Rock Project Cost Breakdown
Material cost is only one part of a rock landscaping project. Delivery, fabric underlayment, edging, and labor all add to the total. Every component below should appear on a legitimate landscaping contractor quote.
| Cost Component | Cost Range | % of Total | Notes |
|---|---|---|---|
| Rock material (per ton) | $35 – $120/ton | 35 – 55% | Varies by rock type and local availability |
| Delivery | $50 – $200 flat fee | 10 – 20% | Most suppliers have minimum delivery tonnage |
| Landscape fabric | $0.05 – $0.30/sq ft | 3 – 8% | Required for weed suppression under decorative rock |
| Edging / borders | $1.50 – $5/linear ft | 5 – 12% | Steel, aluminum, or plastic; prevents rock spread |
| Site prep / grading | $0.50 – $2/sq ft | 5 – 10% | Leveling and slope correction before rock placement |
| Labor (spreading) | $50 – $100/ton | 20 – 35% | Manual spreading and grading; varies by site access |
| Weed treatment | $0.10 – $0.30/sq ft | 2 – 5% | Pre-emergent herbicide before fabric and rock installation |
Rock Calculator Formulas: Manual Calculation
Use these formulas if you prefer to calculate without a calculator tool. All measurements should be converted to feet before calculating.
Step 1 — Calculate Volume in Cubic Feet
Volume (cubic feet) = Length (ft) × Width (ft) × Depth (ft)
Note: Convert depth from inches to feet by dividing by 12. Example: 3 inches = 3 ÷ 12 = 0.25 feet
Step 2 — Convert to Cubic Yards
Cubic yards = Cubic feet ÷ 27
Example: A 20 × 15 ft bed at 3 inches deep = 20 × 15 × 0.25 = 75 cubic feet ÷ 27 = 2.78 cubic yards
Step 3 — Convert to Tons
Tons = Cubic yards × (lbs per cubic yard ÷ 2,000)
Example using river rock (2,800 lbs/cu yd): 2.78 cu yd × (2,800 ÷ 2,000) = 2.78 × 1.40 = 3.89 tons
Step 4 — Add 10% Waste Factor
Order Quantity = Calculated tons × 1.10
A 10% overage prevents running short due to uneven depth, spillage, or irregular area shapes. Excess rock is easy to store or use elsewhere; running short mid-installation causes delays and delivery surcharges.
Bulk Rock vs. Bagged Rock: Cost Comparison
Bagged rock from home improvement stores appears convenient but costs 3 to 6 times more per ton than bulk delivery for any project over 2 tons. For most residential landscaping projects, bulk delivery is the correct choice.
| Rock Type | Bagged (50 lb bag) — per ton | Bulk Ton Bag | Bulk Delivery (5+ tons) | Best For |
|---|---|---|---|---|
| Pea gravel | $300 – $500 | $120 – $200 | $35 – $80 | Over 2 tons → bulk |
| Crushed granite | $350 – $600 | $140 – $220 | $40 – $90 | Over 2 tons → bulk |
| River rock | $400 – $700 | $150 – $250 | $50 – $120 | Over 1.5 tons → bulk |
| Lava rock | $500 – $900 | $200 – $350 | $80 – $160 | Over 1 ton → bulk |
How to Hire a Rock Landscaping Contractor
- Verify contractor license: landscaping contractors require a separate license from general contractors in most states
- Ask for weight tickets: all bulk rock deliveries should include a certified scale ticket showing actual weight delivered
- Confirm fabric and edging is included: many low quotes exclude these and add them as change orders after site prep
- Review the drainage plan: for drainage rock installations, verify slope direction and outlet point before work begins
- Get at least 3 quotes: rock landscaping prices vary widely between contractors; the middle quote is usually the most reliable
- Ask about waste disposal: if existing mulch, grass, or old rock is being removed, confirm whether removal and hauling is included
- Check delivery windows: bulk rock often requires a dump truck; confirm your driveway or gate can accommodate the vehicle size
Related tools and guides: gravel calculator, fill dirt calculator and yardage calculator.
Frequently Asked Questions
At 2 inches deep, 1,000 square feet requires approximately 6 to 7 tons of standard gravel (pea gravel, river rock, or crushed granite). At 3 inches deep, the same area needs 9 to 10 tons. Lava rock covers more area per ton due to its lower density — the same 1,000 square feet at 2 inches requires only 4 to 5 tons of lava rock.
Cubic yards measure volume (how much space the rock takes up). Tons measure weight (how heavy it is). The two are connected by density, which is why different rock types need different tonnage for the same cubic yardage: a cubic yard of lava rock weighs about 1,500 lbs, while a cubic yard of river rock weighs about 2,800 lbs. Most suppliers sell and deliver by weight (tons), since delivery trucks are rated by weight capacity, so tons is usually the number that matters for pricing. Cubic yards is more useful for confirming a delivery truck can physically hold your order.
It depends on the application. Use 2 to 3 inches for decorative groundcover in beds that already have soil or mulch underneath. Use 4 inches for effective weed suppression when paired with landscape fabric. Use 4 to 6 inches for walkways and light foot-traffic paths. Use 6 to 12 inches for drainage applications, French drains, or as a compacted base layer under pavers, patios, or driveways.
Yes. Break the area into simple shapes (rectangles, triangles, or circles), calculate the volume for each one separately using the formulas above, then add the totals together. For curved or free-form beds, measuring the average length and average width and multiplying those gives a reasonably accurate estimate. Adding the standard 10% waste factor covers most of the small error this method introduces.
Most bulk suppliers charge $50 to $200 as a flat delivery fee within about 20 miles of the quarry or yard, though this varies by region and supplier. Delivery cost typically depends on distance, whether your order meets the supplier's minimum tonnage (often 3 to 5 tons for free or reduced-cost delivery), and whether the site is easily accessible for a dump truck. Orders below the minimum tonnage, or delivered further than the standard radius, usually cost more per ton to offset the trip.
A ton of standard gravel, river rock, or crushed granite covers about 120 square feet at 2 inches deep, or about 80 square feet at 3 inches deep. Lava rock, which is lighter, covers roughly double that area per ton. Use the coverage table above for exact figures by rock type.
A cubic yard of rock covers about 162 square feet at 2 inches deep, or about 108 square feet at 3 inches deep, regardless of rock type — coverage per cubic yard only depends on depth, since a cubic yard is a fixed volume. Coverage per ton is what changes by rock type, since different rocks weigh different amounts per cubic yard.
Multiply your area's length by width in feet, multiply that by your depth in feet (inches ÷ 12), then divide by 27 to get cubic yards. For example, a 300 square foot bed at 3 inches deep needs 300 × 0.25 ÷ 27 = 2.78 cubic yards. Add 10% for waste to get your order quantity.
A cubic yard of landscaping rock typically costs $50 to $150 delivered, depending on rock type, quantity, and distance from the supplier. Decorative or specialty rock (like white marble gravel or lava rock) runs toward the higher end; standard crushed granite or limestone runs toward the lower end.
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