StoneRip Rap Calculator

Rip Rap Calculator

Calculate the amount of rip rap rock needed for erosion control, shoreline protection, and drainage projects. Get accurate tonnage and cost estimates.

Project Dimensions

Ready to calculate

Enter your project dimensions

Rock Size Selection Guide

2-4"

Light duty

Walkway borders, small channels

3-6"

Standard

Most erosion control, drainage

6-10"

Heavy duty

Shorelines, moderate slopes

12-18"

Extra heavy

Steep slopes, high flow areas

Expert Contributors

Why expert review matters

Every calculator is reviewed by certified professionals to ensure accuracy.David Chen's Master Mason, Licensed GC certification ensures professional-grade precision.

Pro Tips

  • Install geotextile fabric underneath to prevent soil migration
  • Larger rocks for steeper slopes and higher water velocity areas
  • Layer sizes: larger rocks on top, smaller rocks as base layer
  • Order 10-15% extra to account for settling and voids

Common Questions

How deep should rip rap be?

Typically 1.5-2x the largest rock diameter. 6-12" for most applications.

Do I need geotextile fabric?

Yes, highly recommended to prevent soil erosion beneath the rocks.

Limestone vs granite?

Granite is harder and more durable; limestone is more common and affordable.

How the Calculator Works

Our rip rap calculator determines the volume needed based on your project dimensions, then converts to tonnage using the density of your selected rock size and material type. We add 10% for settling and voids between rocks. Delivery cost is estimated at $5/mile with a $75 minimum.

Formula

Volume (cu yd) = Length × Width × (Depth ÷ 12) ÷ 27

Tons = Volume × Density × 1.1 (settling factor)

Quick Reference

Weight per cu yd
~1.1-1.4 tons
Common depth
6-12 inches
Price range
$25-65/ton
Extra to order
10-15%