How much does 1 yard of riprap weigh?
One cubic yard of placed riprap weighs about 3,510 pounds, or 1.76 US short tons, using a generic placed density of 130 lb/ft³ that includes the voids between stones: 27 × 130 = 3,510, and 3,510 ÷ 2,000 = 1.755. Rock type and gradation change the weight, so confirm a value for the specified class with the quarry.
Riprap weight per cubic yard and per ton
| Quantity | Value | Arithmetic |
|---|---|---|
| Pounds per cubic yard | 3,510 lb | 27 × 130 |
| Short tons per cubic yard | ≈ 1.76 | 3,510 ÷ 2,000 |
| Cubic yards per short ton | ≈ 0.57 | 2,000 ÷ 130 ÷ 27 |
Why riprap weight varies by stone and gradation
The 130 lb/ft³ value describes a placed blanket, voids included, not a solid stone. A denser rock or a gradation whose smaller stones fill more of the voids weighs more per cubic yard. The site’s table has no value for a specific riprap class, so use the quarry’s figure for the class and gradation in the specification.