Calculator
Formula Used
- Rectangle area: Area = length × width
- Circle area: Area = π × radius²
- Triangle area: Area = base × height ÷ 2
- Base volume: Volume in cubic feet = area in square feet × depth in feet
- Cubic yards: Cubic yards = cubic feet ÷ 27
- Adjusted volume: Final volume = base volume × waste factor × settling factor
- Weight: Pounds = final cubic yards × rock density
- Tons: Tons = pounds ÷ 2000
- Bags: Bags = pounds ÷ bag weight, rounded up
- Total cost: Total = material cost + delivery fee
How to Use This Calculator
- Select the bed shape that matches your project.
- Enter the needed dimensions or use custom area.
- Choose the rock depth and unit.
- Select a rock type or enter custom density.
- Add waste and settling percentages.
- Enter bag weight, pricing, delivery, and truck details.
- Press the calculate button.
- Review volume, weight, bags, trips, pallets, cost, and graph.
- Download the CSV or PDF for your estimate record.
Example Data Table
| Project | Area | Depth | Rock Type | Approx. Volume | Typical Use |
|---|---|---|---|---|---|
| Small flower bed | 120 ft² | 2 in | Pea gravel | 0.74 yd³ | Decorative mulch replacement |
| Front yard border | 250 ft² | 3 in | River rock | 2.31 yd³ | Edging and drainage look |
| Walkway base | 180 ft² | 4 in | Crushed stone | 2.22 yd³ | Stable walking layer |
| Large dry creek | 520 ft² | 5 in | River rock | 8.02 yd³ | Drainage and landscape feature |
Landscape Rock Coverage Guide
Why rock coverage matters
Landscape rock looks simple, yet ordering it can become costly. A bed that is too shallow lets fabric, soil, and weeds show through. A bed that is too deep can trap heat, waste money, and make edging harder. Accurate coverage keeps the project clean and predictable. It also helps you compare bulk deliveries, bagged products, and local supplier quotes.
Plan the area first
Start by measuring the bed shape. Rectangular beds need length and width. Circular beds need diameter. Triangular beds need base and height. Irregular beds can be split into smaller shapes. Add each section together before ordering. Always measure in the same unit. Small errors become large when the area is wide.
Choose the correct depth
Depth depends on rock size and purpose. Small pea gravel often works at two inches. Larger river rock usually needs three inches or more. Walkways may need a thicker base. Decorative borders may need less depth. The calculator converts depth into feet, then multiplies it by area. That creates the base volume.
Add waste and settling
Real projects need an allowance. Rock settles after raking and foot traffic. Edges also lose material during spreading. A waste factor of five to ten percent is common for neat beds. Complex shapes may need more. Compaction allowance adds extra volume when the rock packs down. These fields help prevent a second delivery.
Estimate weight and cost
Suppliers often sell landscape rock by cubic yard, ton, or bag. The calculator converts volume into weight using density. Dense crushed stone weighs more than lava rock. You can select a common material or enter a custom density. Then enter your price method, delivery fee, bag size, truck capacity, and pallet quantity. The result shows volume, tons, bags, trips, pallets, and estimated cost. Use the chart to see how depth changes volume. Use the table to compare practical examples before buying.
Before checkout, confirm delivery access, dump location, edging height, drainage slope, and color batch. A final check reduces returns, delays, and cleanup after spreading.
FAQs
1. How deep should landscape rock be?
Most decorative beds use two to three inches. Larger rock usually needs a deeper layer. Walkways and drainage areas may need more depth for stability and coverage.
2. Should I add waste allowance?
Yes. Add five to ten percent for spreading loss, uneven ground, edge gaps, and settling. Complex shapes or sloped areas may need a higher allowance.
3. Is rock sold by weight or volume?
Bulk rock is often sold by ton or cubic yard. Bagged rock is sold by bag weight. This calculator supports all three pricing methods.
4. Why does density matter?
Density converts volume into weight. River rock, crushed stone, lava rock, and marble chips have different weights. Supplier density gives the most accurate estimate.
5. How many bags are on a pallet?
Many pallets hold about 56 bags, but this varies by brand and bag size. Enter your supplier value for better pallet planning.
6. Can I use this for irregular areas?
Yes. Split the area into rectangles, circles, or triangles. Add the parts together, then enter the total using the custom area option.
7. Does the calculator include delivery cost?
Yes. Enter the delivery fee field. The final estimate adds delivery to material cost, giving a more realistic project budget.
8. Is this estimate exact?
It is a planning estimate. Actual needs depend on rock size, moisture, grading, compaction, supplier measurements, and how evenly material is spread.