Landscape Rock Calculator
Calculate landscape rock for several beds, borders, paths and islands at once — each area gets its own shape and depth, and the totals are added for you.
Result
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Enter your measurements and calculate to see volume in cubic yards, cubic feet, and cubic metres.
How this calculator works
Each area is calculated separately — its own shape, measurements and finished depth — and the volumes are added together. The result shows a line for each area and the total.
Total volume = Σ (Area × Finished depth) for each area
Areas can be rectangles, circles, triangles or a measured area. Different areas can use different depths.
Area used = Measured area − Excluded areas
Optional exclusions — a tree ring or a planter, for example — are measured flat areas removed through that area’s full depth. They are not the volume of an object.
Name each area — “front bed”, “path”, “island” — so the result is easy to check against your plan.
Planning a landscape rock project
Break the yard into simple shapes
Most beds are not perfect rectangles. Split each one into shapes you can measure: a rectangle for the straight run, a circle or half-bed for a rounded end, a triangle for a corner. Or measure an irregular bed's area directly and use Known area. The calculator does not draw or map shapes.
Use the depth each area needs
A path and a planting bed may not need the same depth. Enter the finished depth you plan for each area; this calculator does not recommend one.
Mixing products
If different areas use different rock, calculate them as separate totals so you can order each product. For a single material, the Pea Gravel and River Rock calculators add material-specific guidance. For a single area of any material, use the Gravel Calculator.
Weight
Weight needs the bulk density of the actual product. Enter your supplier's figure after calculating the volume; it applies to the combined order volume.
Worked example
Example: a bed, an island and a path
- Front bed: 12 ft × 6 ft at 3 in → 72 ft² × 0.25 ft = 18.0 ft³
- Round island: 6 ft diameter at 3 in → π × 3² = 28.27 ft² × 0.25 ft = 7.07 ft³
- Path: 20 ft × 3 ft at 2 in → 60 ft² × 0.1667 ft = 10.0 ft³
- Total: 18.0 + 7.07 + 10.0 = 35.07 ft³ ÷ 27 = 1.30 yd³
Result: 1.30 cubic yards (0.99 cubic metres) across three areas. The depths are example inputs.
Frequently asked questions
Can each bed have a different depth?
Yes. Every area has its own finished depth field.
How do I handle a curved bed?
Approximate it with simple shapes — for example a rectangle plus a half circle — and add each as its own area. Or measure the bed’s area and enter it as a Known area.
Can I subtract a tree or a planter from a bed?
Yes. Open Exclusions in that area and add the obstacle’s measured footprint as a rectangle, circle, triangle or known area. It is removed through the area’s full depth. Exclusions cannot add up to more than the area itself.
Why does the weight need my supplier’s density?
“Landscape rock” covers many different stones. Their bulk densities differ, so the calculator only estimates weight from the figure your supplier gives for the product you buy.
Sources & methodology
Volumes are geometry plus unit conversion. Sources relevant to this page:
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NIST Guide to the SI (SP 811), Appendix B.8 — Factors for units listed alphabetically
Used in calculations: Length conversion constants used in every calculation.
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ASTM C29/C29M-17a — Standard Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate
Methodology only: Explains that bulk density includes the spaces between particles and differs between loose and compacted conditions.