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River Rock Calculator
Calculate how much river rock you need to cover a garden bed, path, or drainage area.
sq ft
in
lb per bag
What this calculator does
This tool estimates how much river rock you need to cover a landscaping area at a given depth, giving both a total weight in tons and an approximate number of bags.
The formula
Volume = area × depth (in feet). Weight = volume × an average river rock density of about 100 lb per cubic foot (roughly 1.35 tons per cubic yard, typical for washed decorative gravel). Bag count divides total weight by your bag size.
Density can vary by rock size and moisture; bulk (bulk delivery by the ton or yard) is usually more cost-effective than bags for larger areas.
Last reviewed August 2026