Rock Bed Calculator
lb/ft³
cubic ft
lbs
How to Calculate Rock Bed Requirements
To calculate the amount of rock needed for a bed, follow this formula:
Formula for Rock Volume
Volume = Length × Width × Depth
Weight Calculation
Weight = Volume × Rock Density
Where:
- Length, Width, and Depth are measured in consistent units (e.g., feet or meters).
- Rock Density varies by type, typically ranging from 100 to 160 lb/ft³ for most landscaping rocks.
Example:
You want to create a rock bed that is 10 feet long, 5 feet wide, and 0.5 feet deep with a rock density of 120 lb/ft³.
- Calculate the volume:
Volume = 10 × 5 × 0.5 = 25 cubic feet - Determine the weight:
Weight = 25 × 120 = 3,000 lbs
You’ll need approximately 25 cubic feet of rock weighing 3,000 pounds.
Common Types of Rocks for Landscaping
| Rock Type | Average Density (lb/ft³) | Uses |
|---|---|---|
| River Rocks | 100–120 | Decorative beds, pathways, drainage |
| Crushed Granite | 110–130 | Driveways, walkways, and patios |
| Pea Gravel | 90–100 | Playgrounds, gardens, and walkways |
| Lava Rocks | 70–80 | Mulching, drought-resistant landscaping |
