Landscape Rock Calculator

About the Landscape Rock Calculator

This landscape rock calculator estimates the net and adjusted volume of decorative stone, cubic yards, approximate weight, whole purchase units, and project cost. It is useful for garden beds, walkways, drainage zones, and driveway or landscape-rock planning.

Formula and assumptions

Net volume = length × width × depth ÷ 12. Adjusted volume = net volume × (1 + waste ÷ 100). Cubic yards = adjusted cubic feet ÷ 27. Weight = adjusted volume × density. Purchase units = round up adjusted volume ÷ unit yield. Total cost = units × unit price + delivery and labor.

Worked example

For a 20 ft × 10 ft bed at 4 inches deep, net volume is 66.67 ft³. With 10% waste or compaction, order 73.33 ft³, or 2.72 yd³. At 0.6 ft³ per unit, round up to 123 units. At 145 lb/ft³, the estimated weight is about 10,633 lb. With $7 per unit plus $150 delivery and labor, the estimated total is $1,011.

Measurement checklist

• Divide irregular beds into rectangles.
• Measure depth at several points and use the planned finished depth.
• Subtract areas occupied by edging, plants, and structures.
• Confirm whether the supplier sells bags, buckets, or bulk cubic yards.
• Plan safe delivery access for heavy rock.

Manual calculation steps

1. Calculate every section volume.
2. Convert depth from inches to feet.
3. Add sections and apply waste or compaction.
4. Convert cubic feet to cubic yards by dividing by 27.
5. Divide by the supplier yield and round up.
6. Add material, delivery, labor, and tax costs.

Common mistakes

• Using depth in inches without converting to feet.
• Confusing cubic feet with cubic yards.
• Using the wrong density for the stone type.
• Rounding down purchase units.

Frequently asked questions