How much river rock do you need?
Add your areas, pick the stone size, get tons, cubic yards and bag count instantly.
How do I calculate how much river rock I need?
Multiply the area by the depth to get the volume, then convert it to cubic yards and tons. A 10 ft by 10 ft bed covered 3 inches deep takes 25 cubic feet: about 0.93 cubic yards, roughly 1.2 tons of river rock, or 50 bags of 0.5 cubic feet, before any extra.
How much does a cubic yard of river rock weigh?
About 1.2 to 1.35 tons when loose. The EPA volume-to-weight table lists loose rock at 2,570 lb a cubic yard and pebbles at 90 to 100 lb a cubic foot, and the Minnesota DOT counts one-size stone at 1.35 tons a yard. Those tables do not split river rock by stone size, so the calculator starts at 1.3 tons for every size. Wet rock weighs more. If your supplier quotes a weight, enter it in the Weight field.
How deep should river rock be?
Go about 1½ to 2 times the size of the stones: roughly 2 inches for small ¾ to 1½ inch rock, 3 inches for 1 to 3 inch rock and 4 inches for 3 to 5 inch rock. Dry creek beds and drainage runs along a foundation take 4 to 6 inches. Lay landscape fabric underneath to keep weeds and soil from coming up through the stones.
How much area does a ton of river rock cover?
At 1.3 tons a cubic yard, a ton of river rock is about 0.77 cubic yards. Spread 3 inches deep it covers roughly 83 square feet; at 2 inches, about 125 square feet. Larger stones need a deeper layer, so a ton covers less ground.
Should I buy river rock in bags or in bulk?
A cubic yard is 54 bags of 0.5 cubic feet, so bags only make sense for small spots — a planter, a border, a few steppers. For a bed or a dry creek, bulk by the ton or the yard is almost always cheaper, even with a delivery fee. Enter your local prices above to see where the line falls.
How much extra river rock should I order?
River rock barely compacts, but it fills low spots and settles into soft soil, so 5 to 10% extra covers most beds. For a dry creek bed with an uneven bottom, add 10 to 15%. Bulk rock is sold in half or whole tons, so round up.
Sources: U.S. EPA, Standard Volume-to-Weight Conversion Factors; Minnesota DOT, Grading and Base Manual, 5-692.430 (soil and aggregate conversion factors). How we check our calculators.