Landscape Rock Calculator
Estimate landscape rock volume from area and depth.
Landscape Rock Formula
For feet and inches, cubic yards = length × width × depth(in) ÷ 324.
How to Estimate Landscape Rock Volume
Landscape rock quantity is based on the surface area and the planned installation depth. Multiply area by depth to get volume, then convert that volume to cubic yards or an estimated weight using the density of the selected rock.
Landscape Rock Example
A 400 ft² bed covered 2 inches deep uses about 66.7 cubic feet, or roughly 2.47 cubic yards before adding an allowance for uneven ground or settling.
Rock Size and Density
Pea gravel, river rock and larger decorative stone can have different bulk densities and coverage characteristics. Supplier coverage charts are useful when converting cubic yards to tons or bags.
Frequently Asked Questions
How deep should landscape rock be?
The appropriate depth depends on rock size, weed-control goals and the intended use of the area.
Should I use landscape fabric?
It can help separate stone from soil in some applications, but site conditions and drainage should guide the choice.
Should I order extra?
A modest extra allowance is useful for low spots, settling and measurement uncertainty.
Calculation Assumptions and Practical Limits
Landscape-rock estimates start with area and average depth, then convert volume to the purchasing unit. Rock size, void space, compaction, uneven grade and supplier density can make delivered tonnage differ from a simple geometric estimate.