Calculate riprap stone sizing using Isbash, USACE, HEC-11, or Maynord methods. Determine D50 median stone size, gradation requirements, and blanket thickness for channel protection.
| Class | D50 (in) | Application |
|---|---|---|
| Class I | 6-9 | Light duty, low velocity |
| Class II | 9-15 | Medium duty |
| Class III | 15-21 | Standard protection |
| Class IV | 21-27 | Heavy duty |
| Class V | 27-36 | Very heavy duty |
| Class VI | 36-48 | Severe conditions |
| Condition | C |
|---|---|
| Loose, minimum stability | 0.86 |
| Loose, average | 1 |
| Loose, stable | 1.2 |
| Placed, stable | 1.4 |
| Keyed (embedded) | 1.6 |
Select a sizing method and enter flow parameters to determine riprap requirements.
Educational Purpose: The calculations provided by DrainageCalculators.com are for informational and educational purposes only. While we strive for accuracy, these tools do not substitute for professional engineering judgment or designs stamped by a licensed Professional Engineer (PE) where required by law.
Professional Certification: Users are solely responsible for verifying all calculations, confirming compliance with local codes and regulations, and determining the appropriateness of any methodology for their specific application. Critical infrastructure and public safety projects require review and certification by a licensed Professional Engineer.
Limitation of Liability: DrainageCalculators.com, its owners, operators, and contributors assume no liability for damages or losses arising from the use of these calculators. By using this tool, you acknowledge that you have read, understood, and agreed to these terms.
This disclaimer applies to the Riprap Sizing Calculator calculator and all associated calculations.
PE Stamp Required: Many jurisdictions require drainage designs to be reviewed and stamped by a licensed Professional Engineer. Check your local requirements before using these calculations for construction or permit applications.