Free river rock calculator for decorative stone. Enter bed size and depth for cubic yards, tons (~1.35 tons/cu yd), and truck loads.
Reviewed by Sarah Mitchell, Landscape Contractor · Last updated: May 2026
Dry creeks look great on paper until you're short a ton at the tail end of the channel. Measure the flow-line rectangle where stone sits deepest—not the average width across soggy banks. This takeoff spits out cubic yards and tons for smooth river rock; fabric, edging, and spill aren't in the volume line.
Channel depth. Five inches in the flow line hides fabric and reads like a creek; two inches on the banks is a different polygon—don't average them into one depth.[1]
Size grade. 1–3 in mixes nest tighter than cobble—you'll need more yards if the spec jumps to 4–6 in for visibility.
Tons per yard. Smooth river runs plan near 1.35 t/yd loose—verify on the scale ticket, not a web guess.[2]
Underlayment. Non-woven fabric under the channel is sq ft math—order it beside the rock PO.
Delivery minimums. Three yards on paper may still trigger a six-yard truck—waste toggle helps on tight residential jobs.
Example: A 22 ft × 9 ft dry creek channel at 5 in depth → 22 × 9 × (5÷12) = 82.5 cu ft ÷ 27 ≈ 3.06 cu yd. Ten percent waste ≈ 3.36 yd. At 1.35 t/yd ≈ 4.5 tons on the delivery slip.
Cubic yards = Length × Width × Depth (ft) ÷ 27
With waste: Order yd = Volume × (1 + Waste% ÷ 100)
Tons: Tons = Order yd × tons/yd (editable density; river preset 1.35 t/yd[2])
Cost estimate: Cost = Tons × price per ton (local market pricing—confirm with yard)
Area × depth → cubic feet → ÷ 27 = cubic yards. River rock is often sold by the ton at roughly 1.35 tons per cubic yard. Typical decorative depth is 3–4 inches; dry creek features may use 6+ inches in the channel.
About 3.06 cu yd base; with 10% waste plan ~3.4 yd or ~4.5 tons at 1.35 t/yd.
Often yes for a decorative dry creek—deeper if you need to hide pipe or handle real storm flow.[1]
Either works—convert with the scale weight on the ticket. This tool shows both.[2]
Same volume formula, different density—use our pea gravel calculator for smaller round aggregate paths.
Decorative channels stay loose. Light tamping is for paths—follow the designer spec on the plan set.
Estimates are based on decorative aggregate industry standards. Actual quantities may vary by ±10% depending on site conditions, spread depth, and supplier tonnage factors. Always confirm with your stone yard before ordering.