Free calculator
River Rock Calculator
Use this river rock calculator to estimate cubic feet, cubic yards, tons, bag count, coverage, and a simple cost placeholder from length, width, depth, density, and waste. It builds a printable material list for beds, borders, and dry creek bed projects before you order bagged or bulk stone.
EstimateEstimate only; supplier material density, stone size, moisture, edging, and local drainage conditions vary.
Project inputs
Estimate
1.07 cubic yards of river rock
A 160 sq ft area at 2 inches deep needs about 1.07 cubic yards, or 1.5 tons, of river rock after 8% extra.
Printable material list
Estimate- River rock1.07 cu yd8% waste included
- River rock by weight1.5 tons1.4 tons/cu yd density
- Bagged river rock60 50-lb bagsround up before buying
- Bulk cost placeholder$69.55$65/cu yd assumption
- Coverage at 2 inches172.8 sq ftspread thinner or deeper to change coverage
Estimate only. Rounded river rock packs differently than crushed stone, and supplier density and stone size vary.
Visible defaults
Assumptions
- Default river rock density is about 1.40 tons per cubic yard.
- Cubic yards equal cubic feet divided by 27.
- Bag count uses your selected bag weight and rounds up to whole bags.
- Cost is a placeholder using your entered bulk price, not a quote.
Math
Calculation details
- Area = length x width.
- Cubic feet = area x depth in feet.
- Cubic yards = cubic feet / 27.
- Tons = cubic yards x density.
What this river rock calculator does
River rock is sold a few ways. You might see it bagged by the pound, bulk by the cubic yard, or on delivery tickets by the ton. This calculator keeps those units aligned. Enter the bed footprint, depth, density, bag weight, and waste, and it returns cubic feet, cubic yards, tons, bag count, coverage, and a simple bulk cost placeholder for planning.
It fits decorative beds, borders, tree rings, dry creek beds, and drainage-look channels where rounded stone is the visible finish. It does not decide whether river rock suits a particular drainage or traffic situation. It turns a measured area into a practical shopping list with every assumption shown so you can sanity-check the numbers.
How deep should river rock be?
River rock stones are rounded and often larger than pea gravel, so a thin layer can look sparse and let fabric or soil show through. Two to three inches is a common planning depth for decorative beds, and larger stone sizes lean toward the deeper end. Dry creek beds are usually deeper in the channel center than along the edges, so estimate those zones separately.
Depth drives the order quantity directly. A 100 square foot bed at 2 inches is about 16.7 cubic feet before waste, and the same bed at 3 inches is 25 cubic feet. When the project sits near a bag or delivery threshold, confirming depth first helps avoid both a shortage and a leftover pile of stone you have to store.
Formula used
The calculator multiplies length by width for square feet, then by depth in feet for cubic feet. Cubic yards equal cubic feet divided by 27. Tons equal cubic yards times the density you enter. Bag count converts tons to pounds, divides by your bag weight, and rounds up. Waste is added on top before the final quantities.
Density is the least universal input. River rock density shifts with stone size, gradation, rounding, moisture, and source. The 1.40 tons per cubic yard default is a planning value, and rounded river stone usually differs from crushed gravel. If a local yard lists a different conversion, type that number into the density field instead.
Bagged versus bulk river rock
Bagged river rock suits small beds, tight access, and projects where delivery costs more than it saves. Bulk stone is usually easier for larger beds and long dry creek beds, but it needs a clear dump spot and a plan for moving it by wheelbarrow. The calculator shows both so you can compare the scale of the job before choosing how to buy.
The optional cost field stays deliberately simple. It multiplies cubic yards by your entered price per cubic yard. It excludes delivery, pallet deposits, regional pricing swings, taxes, minimum orders, and supplier fees. Treat it as a way to compare two scenarios on the same screen, not as a finished supplier price for the load.
Common mistakes
The most frequent error is treating square feet as cubic feet and skipping depth. Another is confusing tons with cubic yards: a cubic yard is volume, a ton is weight, and the link between them is density, so two suppliers can quote different tonnage for the same bed. Larger river rock also packs loosely, which nudges real-world coverage below tidy table values.
It is easy to forget landscape fabric, edging, and base prep. Those items are not in the stone number but they shape the finished bed. Underestimating dry creek bed depth at the channel center is common too. The printable list gives stone quantities and assumptions, leaving room to add fabric, staples, edging, and tools.
Before you order
Take the printed list, bed dimensions, chosen stone size, and site notes to the supplier. Ask whether their density, bag weight, and stone size match the calculator assumptions, because rounded river stone and crushed product behave differently. If the numbers differ, update the density field and recompute rather than guessing at the register from memory.
Keep the disclaimer with the list. It is a planning estimate, and supplier material and local conditions vary. If the project affects drainage flow, slope stability, runoff onto a neighbor, or a structure, get local advice first. Order edging, fabric, and any base material separately, since this estimate covers the decorative stone only.
Quick reference
River rock coverage by depth
| Depth | Coverage per cubic yard | Coverage per ton |
|---|---|---|
| 1 in | 324 sq ft | 231 sq ft |
| 2 in | 162 sq ft | 116 sq ft |
| 3 in | 108 sq ft | 77 sq ft |
| 4 in | 81 sq ft | 58 sq ft |
Based on 1 cubic yard = 27 cubic feet and a planning density of 1.4 tons per cubic yard. Rounded river stone differs from crushed, and supplier density varies.
FAQ
River Rock Calculator FAQ
How do I calculate river rock needed?
Multiply length by width for square feet, multiply by depth in feet for cubic feet, then divide by 27 for cubic yards. Add a waste factor, then convert to tons or bags using the density and bag weight.
How many square feet does a cubic yard of river rock cover?
One cubic yard is 27 cubic feet. At 2 inches deep it covers about 162 square feet before waste, and at 3 inches deep it covers about 108 square feet before waste.
How many tons are in a cubic yard of river rock?
A common planning value is about 1.4 tons per cubic yard, but density varies with stone size and source. Use the supplier conversion when you order by weight.
How deep should a dry creek bed be?
Dry creek beds are usually deeper at the channel center than the edges, so estimate the center and sides separately. A planning estimate is no substitute for local advice when real water flow is involved.
Should I buy river rock in bags or bulk?
Bags suit small beds and tight access. Bulk ordering is usually better for larger beds and dry creek beds, but watch delivery minimums, the dump location, and the labor to move heavy stone.
Does the calculator include landscape fabric?
No. It estimates the decorative stone quantity only. Add landscape fabric, staples, edging, base material, and tools separately based on the actual bed and site conditions.
Methodology
Who built and reviewed this estimate
Keep planning