Free river rock calculator — cubic yards, weight and cost
Work out how much river rock to order for beds, borders, dry creek beds or drainage. Add as many areas as you need and get cubic yards, tons and cost.
How deep should river rock be?
Two inches works for a decorative border where you just want coverage. Three inches is the usual depth for beds, and it is where river rock starts genuinely suppressing weeds. Four inches or more belongs in dry creek beds and drainage runs where you want water moving through the voids.
Stone size changes the depth you need. Larger cobbles — three inches and up — need proportionally more depth simply to sit as a continuous layer rather than a scattering.
Put fabric down first. River rock is expensive and permanent-feeling, but without a weed barrier underneath it slowly sinks into the soil and fills with organic debris, and getting it back out again is genuinely miserable work.
Coverage at a glance
How far one cubic yard goes, and what 1,000 square feet takes, at each common depth:
| Depth | One cubic yard covers | 1,000 sq ft needs |
|---|---|---|
| 2" | 162 sq ft | 6.2 cu yd |
| 3" | 108 sq ft | 9.3 cu yd |
| 4" | 81 sq ft | 12.3 cu yd |
Weight and delivery
River rock runs about 1.4 tons per cubic yard. It is one of the more expensive bulk landscape materials, so it is worth measuring carefully rather than rounding up generously.
Before you order, check access. Bulk material is tipped, not carried — the truck needs room to back in and raise its bed, and most suppliers will not tip on a surface they might damage. Ask about the delivery fee and the minimum order separately, because both change the maths on small jobs.
Turn it into a quote
Hit Copy order and the whole breakdown goes to your clipboard, ready to paste into an estimate. Add your labour, price it with the profit margin calculator, and send it with the estimate generator.
Related: cubic yard calculator, gravel, topsoil, mulch and concrete calculators, plus state-by-state rate data for what landscapers and contractors earn.
FAQ
How much river rock do I need?
Multiply area by depth in feet and divide by 27. At the common 3 inch depth, one cubic yard covers 108 square feet. A 200 square foot bed at 3 inches needs about 1.9 cubic yards.
How much does a yard of river rock weigh?
Around 2,800 pounds, or about 1.4 tons — similar to gravel, since it is the same material by density, just naturally rounded rather than crushed.
Does river rock need landscape fabric underneath?
Yes, in almost every case. Without a barrier the rock migrates into the soil over a few seasons and collects organic debris that weeds then root into. Removing embedded river rock later is far more work than laying fabric now.
Is river rock better than mulch?
They solve different problems. River rock does not decompose so it never needs topping up, and it will not wash away on a slope. But it does not feed the soil, it reflects heat onto plants, and it is much harder to remove if you change your mind. Mulch is better for planting beds; rock is better for drainage and low-maintenance borders.
What size river rock should I use?
Three-quarter inch to one and a half inch is the general-purpose range for beds and borders. Larger cobbles suit dry creek beds and erosion control. Smaller pea-sized stone is comfortable underfoot but migrates easily, so it needs edging.