What this calculator does
This tool estimates how many tons of rip rap (large angular stone used for erosion control on slopes, ditches, and shorelines) you need to order, based on the area to cover and the placement thickness.
The formula
Volume = length × width × thickness (in feet). Weight = volume × density (typically 150 to 175 lb per cubic foot for rip rap, depending on stone type). Tons = weight ÷ 2000.
Placement thickness should generally be at least 1.5 to 2 times the diameter of the largest stones used. Always round up and check with your supplier’s specific stone density for best accuracy.
Last reviewed August 2026