River Rock Calculator
Quickly estimate cubic yards, tons, and material cost for your River Rock project. Adjust the inputs below and the result updates in real time.
Calculate Your Project
Estimate only. Add 10-15% for compaction and waste.
How this calculator works
River rock is priced and delivered, by the ton, not by volume.
This river rock calculator turns your area and depth into the number of tons of river rock to order, using the material's real density instead of a generic estimate. Enter your length, width and target depth and the calculator converts that volume into cubic yards, then into tons, so you know exactly what to order for delivery.
How the River Rock Calculator Works
The calculator multiplies length in feet by width in feet by depth in inches, then divides by 324 to get cubic yards. From there it applies river rock's density to convert that cubic yard figure into tons, the unit river rock is sold and delivered by. You get a straight ton figure to hand to whoever is placing your order, with no separate math required on your end.
Recommended Depth for River Rock
Depth is the number that changes your tonnage the most, so it is worth getting right before you run the numbers. A shallow layer around 2 inches deep works for a decorative top dressing over an existing base. A depth of 3 to 4 inches is the more common target when river rock is doing the work of covering ground on its own, since a thinner layer lets soil and roots show through over time. Larger stone, in the 1 to 3 inch range or bigger, generally needs the deeper end of that range to sit properly and stay in place.
River Rock Density and the Yards to Tons Conversion
River rock runs about 100 pounds per cubic foot, which works out to 2,700 pounds in a cubic yard, heavier than many landscape stones because the rounded pieces pack together tightly. Divide 2,700 by 2,000 pounds and one cubic yard of river rock weighs about 1.35 tons. That factor is what the calculator uses to turn your cubic yard total into the tons figure on your order. If you already have a cubic yard number from another source and just need the ton equivalent, use the cubic yards to tons converter, once to check it against a different material's weight.
Ordering Tips and How Much Extra to Buy
Round up rather than down. Irregular edges, low spots and settling after the first rain all eat into coverage, and river rock is far easier to order once than to reorder in a small top up load. Adding 5 to 10 percent on top of the calculator's number covers most of that variance without leaving you with a large surplus pile. Measure the area at its actual shape rather than a rough rectangle when the space has curves, and if depth varies across the space, use the deepest point as your planning number. For the material itself, see the River Rock product page for sizes and delivery details before you place an order.
Materials this calculator covers
From $54.20/ton- Size1 - 3″
- Density2700 lb/yd³
- ColorMixed natural
From $71.79/ton- Size0 - 1/4″
- Density3000 lb/yd³
- ColorTan, gold
From $43.24/ton- Size3/8″
- Density2800 lb/yd³
- ColorMixed earth
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How much river rock do I need for my project?
Multiply the length and width of the area in feet to get square footage, then use this calculator with your target depth to convert that area into cubic yards and then tons. For a typical 3 inch layer, figure roughly half a ton of river rock for every 15 to 20 square feet, then round up to account for uneven ground and settling.
How much does a yard of river rock weigh?
One cubic yard of river rock weighs about 2,700 pounds, which works out to 1.35 tons. That is heavier than many landscape stones because the rounded, evenly sized pieces settle together with fewer gaps than angular gravel. The calculator uses this exact weight to convert the cubic yards your project needs into the tons figure you actually order.
What depth should I use for 2 inch river rock in the calculator?
A 2 inch layer works well as a decorative top dressing over an existing base or landscape fabric, since the stone itself is not carrying much structural or weed control load. If the river rock is the only ground cover, plan on 3 to 4 inches instead so soil and roots do not show through as the layer settles.
How many tons are in 1 cubic yard of river rock?
One cubic yard of river rock comes to about 1.35 tons, based on a density of 2,700 pounds per cubic yard divided by 2,000 pounds per ton. That ratio is fixed for this material, so once you know your cubic yard total from the calculator, multiplying by 1.35 gives you the ton figure to order.
Does 1 to 3 inch river rock need a different depth than smaller stone?
Yes. Larger river rock, closer to a half inch to 1 inch, can cover effectively at 2 inches since the pieces settle into a tighter, more stable layer at a shallower depth.
Can I run the river rock calculator using square feet instead of length and width?
Yes. If you already know the square footage of the area, enter it directly along with your target depth and the calculator will convert that figure into cubic yards and then tons, the same as it would from separate length and width measurements. Either way, depth is what determines the final tonnage the most.