Landscape Rock Calculator
Use this landscape rock calculator to find out how much material your yard needs. Enter your area and depth to instantly get the volume in cubic yards.
The method
volume = area × depth; weight = volume × density
Depth in inches, volume in yards
This is where the arithmetic usually goes wrong. A cubic yard is 27 cubic feet, so spread 4 inches deep it covers 81 square feet — not 27. Divide the depth in inches by 12 before multiplying, or work in a single unit throughout.
Order by volume when you can and treat the weight as a cross-check. Loose densities vary by about 10% between quarries and rise sharply when the material is wet, so a ton of gravel is a less definite quantity than a cubic yard of it.
Add a compaction allowance for anything that will be rolled or tamped. Crusher run and road base typically lose 20–25% of their loose volume once compacted.