🪨 Rip Rap Calculator
Calculate rip rap needed for erosion control
Standard depth: 12-18 inches
Standard size: 12-18 inches
How to Use This Calculator
Enter Area Dimensions
Input the length and width of your area in feet. Measure the area where you'll be installing rip rap for erosion control, slope stabilization, or shoreline protection.
Specify Depth and Rock Size
Select rip rap depth (standard is 12-18 inches) and rock size (standard is 12-18 inches). Deeper layers and larger rocks provide better erosion control but require more material.
Calculate Rip Rap
Click "Calculate Rip Rap" to see the volume needed in cubic yards, cubic feet, tons, and tons per linear foot. The calculator accounts for standard rip rap density.
Order Materials
Use the cubic yards result to order from suppliers. Rip rap is typically delivered by the cubic yard or ton. Add 10% extra for waste and settling. Order larger quantities for better pricing.
Formula
Depth (feet) = Depth (inches) ÷ 12
Volume (cubic feet) = Length (ft) × Width (ft) × Depth (ft)
Cubic Yards = Cubic Feet ÷ 27
Weight (tons) = Cubic Yards × Density (1.5 tons/yd³)
Example 1: Slope Stabilization (50 ft × 3 ft × 12 inches)
Step 1: Convert depth: 12 inches ÷ 12 = 1 foot
Step 2: Calculate volume: 50 × 3 × 1 = 150 cubic feet
Step 3: Convert to yards: 150 ÷ 27 = 5.56 cubic yards
Step 4: Calculate weight: 5.56 × 1.5 = 8.33 tons
Step 5: Calculate per linear foot: 8.33 ÷ 50 = 0.17 tons per linear foot
Example 2: Shoreline Protection (100 ft × 4 ft × 18 inches)
Step 1: Convert depth: 18 inches ÷ 12 = 1.5 feet
Step 2: Calculate volume: 100 × 4 × 1.5 = 600 cubic feet
Step 3: Convert to yards: 600 ÷ 27 = 22.22 cubic yards
Step 4: Calculate weight: 22.22 × 1.5 = 33.33 tons
About Rip Rap Calculator
The Rip Rap Calculator is an essential tool for contractors, engineers, landscapers, and property owners who need to accurately determine how much rip rap (large stones) is required for erosion control, slope stabilization, and shoreline protection projects. This calculator eliminates guesswork by providing precise measurements in cubic yards, cubic feet, and tons, helping you order the right amount of materials without waste or shortages.
When to Use This Calculator
- Erosion Control: Calculate rip rap needed for erosion control on slopes, banks, or hillsides
- Shoreline Protection: Determine materials for shoreline protection along lakes, rivers, or coastlines
- Slope Stabilization: Estimate rip rap for stabilizing slopes or embankments
- Drainage Channels: Calculate materials for rip rap lining in drainage ditches or channels
- Budget Planning: Calculate material costs by determining exact quantities needed
Why Use Our Calculator?
- ✅ Accurate Measurements: Precise calculations prevent over-ordering or running short
- ✅ Multiple Units: Get results in cubic yards (for delivery), cubic feet, tons, and tons per linear foot
- ✅ Weight Estimates: Provides weight calculations for shipping and handling
- ✅ Slope Applications: Shows tons per linear foot for slope stabilization projects
- ✅ Cost Savings: Order the exact amount needed plus waste allowance to avoid excess material
- ✅ Time Efficient: Instant calculations save hours of manual math and measurements
Common Applications
Erosion Control: Contractors and property owners planning erosion control projects use this calculator to order the correct quantity of rip rap. Standard installations use 12-18 inch rip rap at 12-18 inches deep, which this calculator helps determine accurately.
Shoreline Protection: Engineers and contractors planning shoreline protection projects use this tool to estimate rip rap quantities needed. Shoreline protection typically requires larger rip rap (18-24 inches) at greater depths (18-24 inches) for effective wave protection.
Slope Stabilization: Contractors and engineers planning slope stabilization use this calculator to determine rip rap quantities needed, ensuring sufficient materials are on-site before starting work.
Tips for Best Results
- Add Waste Allowance: Always add 10% extra to account for settling and waste
- Depth Recommendations: Standard depth is 12-18 inches; deeper (18-24") for high-velocity areas
- Rock Size: Standard size is 12-18 inches; larger rocks (18-24") for high-energy areas (waves, fast water)
- Foundation: Install on proper foundation (geotextile fabric or gravel base) for stability
- Order by Volume: Rip rap is typically ordered in cubic yards or tons; verify with supplier
Frequently Asked Questions
How much rip rap do I need for a 50×3 foot slope at 12 inches deep?
A 50×3 foot slope at 12 inches deep requires approximately 5.56 cubic yards of rip rap, weighing about 8.33 tons. That's about 0.17 tons per linear foot. Always add 10% extra for settling and waste, so plan for about 6.1 cubic yards or 9.2 tons.
What size rip rap should I use?
Standard rip rap size is 12-18 inches for most erosion control applications. For high-energy areas (wave action, fast-moving water), use larger rip rap (18-24 inches). Rock size should be 2-3× the expected flow velocity or wave height. Consult engineering specifications for specific requirements.
How deep should rip rap be?
Standard rip rap depth is 12-18 inches for most applications. For high-velocity areas or heavy wave action, use 18-24 inches deep. Deeper rip rap provides better erosion protection but requires more material. Check engineering requirements for your specific application.
Do I need a foundation under rip rap?
Yes! Rip rap should be installed on a proper foundation. Use geotextile fabric (filter fabric) or a gravel base layer to prevent soil from washing out from under the rip rap. The foundation helps maintain stability and prevents the rip rap from sinking into the soil.
How much does a cubic yard of rip rap weigh?
A cubic yard of rip rap typically weighs 1.4-1.6 tons (2,800-3,200 pounds), depending on rock size and type. Larger rocks have more air space, so they weigh slightly less per cubic yard. Actual weight may vary by rock type and supplier.
Can I install rip rap myself?
Small projects may be DIY-friendly with proper planning and equipment. Large projects or high-energy areas typically require professional installation with heavy equipment. Rip rap is heavy—ensure you have proper lifting equipment and safety measures in place.