By Zencalcy Editorial TeamLast reviewed About us
Rip rap is graded rock placed to absorb wave and current energy. Its sizing is usually expressed as D50, the median stone diameter, and it is placed in a layer at least 1.5 times that diameter thick. This calculator estimates the volume from an embankment face and reports the tonnage to order.
Stone size and tonnage for embankment and erosion protection.
V = L × W × D W = V × ρ Cost = V × price
Layer depth should be at least 1.5 × D50 so stones interlock in two layers. Bulk density is taken as 1,600 kg/m³ for graded rock; a 25% allowance is common for placement losses on steep banks.
| Symbol | Meaning |
|---|---|
| L, W | Length and width of the area being covered. |
| D | Spread depth of the material. |
| V | Volume in cubic yards (and cubic metres). |
| ρ | Bulk density of the material. |
| W | Total weight, shown in pounds and US tons. |
The face area is 300 sq ft and the volume is 450 cu ft, or 16.7 cu yd — about 22 US tons of rip rap.
Continue with the Gravel Calculator, Sand Calculator, Rock Calculator, or the River Rock Calculator — or browse more materials & quantities and all construction calculators.
D50 of 6–12 inches suits slow-moving ditch flow; 18–24 inches for pond edges exposed to wind waves; 24–36 inches for fast river banks. Local codes usually dictate the minimum.
Results use standard construction estimating arithmetic: volumes from measured area and depth, unit weights from published material densities, and code-referenced spans or clearances where the page names a code. Quantities are rounded up to whole saleable units and include the stated waste allowance. These tools are planning aids, not structural design, and do not replace a licensed engineer, a local code check, or a contractor's site measurement.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026