Figure about 3 cubic yards of rip rap for 20 linear feet of embankment with a 4-foot face, placed roughly one stone — 12 inches — thick. The math: 20 ft × 4 ft = 80 sq ft of face; 80 × 12" ÷ 324 = 2.96, so call it 3 yards and round up if your slope is taller.
Sizing any rip rap job
- Face area = length × slope height, measured along the slope, not the flat ground
- Face area × thickness in inches ÷ 324 = cubic yards
- 6"–12" stone lays about one stone deep at a 12" thickness
Rip rap is dense, so it ships up to 6 yards per truck. Order Rip Rap 6"–12", check numbers with the material calculator, or call or text (617) 645-0987 for bigger banks.
