Landscape Stone Estimator

River Rock Calculator

Free river rock calculator for decorative stone. Enter bed size and depth for cubic yards, tons (~1.35 tons/cu yd), and truck loads.

Advanced Options

Cubic Yards—
Total Tons—
Est. Cost—

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.

What affects river rock quantities?

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.

Worked example

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.

How we calculated this

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)

Calculating river rock volume

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.

Questions & Answers

How much rock for a 22×9 ft dry creek at 5 in deep?

About 3.06 cu yd base; with 10% waste plan ~3.4 yd or ~4.5 tons at 1.35 t/yd.

Is 5 inches enough in the channel center?

Often yes for a decorative dry creek—deeper if you need to hide pipe or handle real storm flow.[1]

Order by ton or cubic yard?

Either works—convert with the scale weight on the ticket. This tool shows both.[2]

Does pea gravel use the same math?

Same volume formula, different density—use our pea gravel calculator for smaller round aggregate paths.

Should I compact river rock in a creek?

Decorative channels stay loose. Light tamping is for paths—follow the designer spec on the plan set.

Sources

  1. Landscape industry practice — decorative ground cover and dry creek channel depth ranges (3–6 in flow lines).
  2. ASTM D75 / supplier scale tickets — aggregate bulk density for ton conversions (product-specific).

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.

How we built this calculator: results use the standard volume, area, and coverage formulas shown on this page, with typical U.S. material densities, bag yields, and waste factors that you can override. Written and checked by the YardsCalculator editorial team. Last reviewed: October 2026.

Cu Yd —
Tons —
Edit