Construction Calculator - Driveway and Sitework

Rip Rap Calculator

Estimate rip rap volume and tons for erosion-control areas.

Reviewed: August 26, 2026

Calculate Rip Rap

For the Rip Rap Calculator, enter length, width, depth, waste allowance, material density, and material price. It multiplies length, width, and installed depth, converts to cubic yards, applies allowance once, and converts volume to tons through the entered bulk density.

Gravel, river rock and sand arranged with measuring and installation tools

Formula used

Cubic yards = [length × width × (depth ÷ 12) ÷ 27] × (1 + waste ÷ 100); tons = cubic yards × density

Rip Rap Calculator measurement plan showing Length feet, Width feet, Depth inches

Worked rip rap example

Rip Rap Calculator example: 38.1 ft × 11.8 ft × (4 in ÷ 12) ÷ 27 = 5.55 yd³ before allowance. After 10% allowance, the order basis is 6.11 yd³, or 10.07 short tons at 1.65 tons/yd³.

Volume, density, and supplier units

Use tons for quarry ordering and confirm that the specified stone class, filter layer, delivery access, and placement equipment match the project.

Field conditions that change tonnage

Large angular rock leaves voids; quarry gradation, layer thickness relative to stone size, slope, toe trenches, bedding, and placement method affect tonnage.

Questions specific to this calculation

Which bulk density belongs in the rip rap tons estimate?

Measure protected area and layer thickness as a rectangular volume, then enter the delivered bulk density for the specified riprap gradation.