River Rock Calculator
Work out how much river rock or landscape rock you need for a bed, border or dry creek bed. Pick the rock size and enter the area to get tons, cubic yards, bags, landscape fabric and a bulk-vs-bagged cost. The depth fills in from the rock size if you leave it blank.
How much river rock do I need for common projects?
1 to 3 in river rock, the most common size. Tons, yards and bags include the 10% waste allowance; bags are 0.5 cu ft.
Rock types: depth, weight, coverage and cost
Recommended depth by rock size, how many square feet one ton covers, and bulk cost per ton and per cubic yard before delivery.
| Rock | Depth | Tons per cu yd | 1 ton covers (2 / 3 / 4 in) | Per ton | Per cu yd |
|---|---|---|---|---|---|
| River Rock, 1 to 3 in | 3 in | 1.28 | 126 / 84 / 63 sq ft | $90–$150 | $115–$192 |
| River Rock, 3/4 to 1 in | 2 in | 1.28 | 126 / 84 / 63 sq ft | $70–$120 | $90–$154 |
| River Rock, 3 to 5 in | 5 in | 1.28 | 126 / 84 / 63 sq ft | $120–$180 | $154–$231 |
| Pea Gravel (3/8 in) | 2 in | 1.30 | 125 / 83 / 63 sq ft | $50–$75 | $65–$97 |
| Mexican Beach Pebbles | 3 in | 1.28 | 126 / 84 / 63 sq ft | $690–$865 | $885–$1,109 |
| Lava Rock | 3 in | 0.61 | 267 / 178 / 133 sq ft | $115–$250 | $70–$152 |
- 3/4 to 1 in river rock and pea gravel: paths, between pavers and small beds. Pea gravel is the cheapest but rolls underfoot.
- 1 to 3 in river rock: the most common size for beds, foundation borders and drainage.
- 3 to 5 in river rock: dry creek beds, downspout splash areas and slopes, placed by hand.
- Mexican beach pebbles: smooth, dark, premium stone, usually a single top layer or an accent.
- Lava rock: light and porous, so a ton covers about twice the area, but it can wash away on slopes.
National-average ranges as of 2026-11, not live quotes. Colored and specialty rock (white, Arizona, Tennessee and so on) varies widely by region. After you calculate your quantity above, you can request local delivered prices. To convert a gravel or stone quote between yards and tons, use our sister site's cubic yards to tons converter; for lava rock, use the tons per cubic yard column above, since it weighs about half as much.
How the river rock calculator works
- Volume: length × width × depth (inches ÷ 12) gives cubic feet, plus a 10% waste allowance. Divide by 27 for cubic yards.
- Depth: if you leave it blank, the calculator uses the depth the rock size needs to cover the ground.
- Tons: cubic feet × the rock's weight per cubic foot ÷ 2,000.
- Bags: cubic feet ÷ 0.5, rounded up.
- Fabric: the area plus 10% for overlapping seams.
- Cost: tons × the bulk price per ton, and bags × the bag price where the rock is commonly sold bagged, each plus fabric.
Worked example
A 10 × 10 ft bed of 1 to 3 in river rock at 3 in deep: 100 × 3 ÷ 12 = 25 cu ft, plus 10% = 27.5 cu ft. That's 1.02 cubic yards, or about 1.31 tons at 1.28 tons per yard. In bulk that's roughly $118–$197 before delivery. In bags it's 55 bags of 0.5 cu ft, about $303–$743, which is why bulk wins once a job reaches about a yard.
Frequently asked questions
How much river rock do I need?
Multiply length by width for square feet, multiply by the depth in feet (inches ÷ 12) for cubic feet, and divide by 27 for cubic yards. Multiply cubic yards by about 1.28 for tons, and add 10% for gaps and spillage. A 10 by 10 ft bed of 1 to 3 in river rock, 3 in deep, needs about 1.31 tons (1.02 cubic yards).
How many square feet does a ton of river rock cover?
About 126 sq ft at 2 in deep, 84 sq ft at 3 in and 63 sq ft at 4 in. Lava rock is much lighter, so a ton covers about 178 sq ft at 3 in.
How many tons are in a yard of river rock?
About 1.28 tons (roughly 2,565 lb) per cubic yard, depending on the stone and how wet it is. Lava rock is about 0.61 tons per yard. Suppliers sell by the ton or by the yard, so ask which before you order.
How deep should river rock be?
Deep enough that the ground or fabric doesn't show: about 2 in for 3/4 to 1 in rock, 3 in for 1 to 3 in rock and 5 in for 3 to 5 in rock. A dry creek bed or path usually gets 3 to 4 in. Deeper than needed wastes rock and money.
How much does river rock cost?
Bulk river rock runs about $70–$120 a ton for 3/4 to 1 in, $90–$150 for 1 to 3 in and $120–$180 for 3 to 5 in, before delivery. That's about $115–$192 per cubic yard for the common 1 to 3 in size. Bagged rock costs about $5.50–$13.50 per 0.5 cu ft bag. Mexican beach pebbles cost far more, about $690–$865 a ton. National ranges as of 2026-11, not quotes.
How many bags of river rock are in a yard?
A cubic yard is 27 cubic feet, so it takes 54 bags of 0.5 cu ft. A ton of river rock is about 42 of those bags. Above about a cubic yard, bulk delivery is usually much cheaper than bags.
Do I need landscape fabric under river rock?
It is not required, but it slows weeds and keeps rock from sinking into the soil. Lay it with about 10% extra for overlapping seams and pin it down before the rock goes on. Skip it where you plan to plant, or cut X-shaped openings for each plant.
Limitations
This tool estimates quantities, weights and typical costs for rectangular areas. For a round bed, use the diameter for both length and width and multiply the result by 0.785. Rock weight varies with the stone, its size and moisture, and prices, delivery minimums and fees vary by supplier, so confirm before ordering. Rock in a drainage channel or on a steep slope may need a contractor's design, not just this estimate.
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