Rip Rap Calculator
Plan your erosion control project with precision. This calculator determines the volume, weight, and cost of rip rap stone needed for shoreline protection, channel lining, and embankment stabilization.
Length of the area to cover with rip rap
Width of the area to cover
Thickness of the rip rap layer
Price per ton of rip rap stone
What is rip rap used for?
Rip rap is a layer of large angular stone used to protect shorelines, riverbanks, embankments, and slopes from water erosion and scour. It absorbs and deflects wave energy, prevents soil loss, and stabilizes slopes. Common applications include bridge abutments, drainage channels, culvert outlets, pond dams, and coastal protection structures.
How thick should a rip rap layer be?
Rip rap layer thickness depends on the application and stone size. For light erosion control: 6-12 inches. For standard channel linings: 12-18 inches. For heavy wave protection: 18-36 inches. Minimum thickness should be at least 1.5 to 2 times the average stone diameter. A geotextile fabric filter layer is recommended beneath the rip rap to prevent soil loss while allowing drainage.
How much does a ton of rip rap cover?
One ton of rip rap stone covers approximately 40 to 60 square feet at a 12-inch depth, depending on stone size and shape. Larger stones have more voids and cover less area per ton. At 6-inch depth, one ton covers about 80-100 sq ft. At 18-inch depth, one ton covers about 25-35 sq ft. Typical rip rap density ranges from 1.2 to 1.4 tons per cubic yard.
What size rip rap stone should I use?
Stone size depends on water velocity and slope. For gentle slopes with low flow: 4-6 inch stone. For moderate channels and banks: 6-8 inch stone. For high-velocity channels and wave action: 8-12 inch stone. For severe coastal erosion: 12-18+ inch stone. The stone should be angular (not rounded), durable, and properly graded. A well-graded mixture with smaller stones filling voids between larger stones provides the best erosion protection.