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Angle of Repose Calculator

Calculate angle of repose from pile geometry or lookup typical values for 12 common materials. Outputs angle, slope ratio, and percent grade.

Last updated 30 June 2026

About this tool

Calculate the angle of repose from measured pile dimensions (height and base radius) or look up typical values for 12 common materials including sand, gravel, crushed stone, topsoil, chalk, Type 1 sub-base, and aggregate.

Outputs include angle in degrees, slope ratio (1:n), and percent grade. Useful for stockpile design, hopper sizing, and estimating natural slope angles for loose materials.

How to use this tool

1. Choose input method — measure from a real pile, or lookup by material type.

2. Enter dimensions or select material — height and base radius for measurement, or pick from the dropdown.

Technical information

θ = arctan(height / base radius)

Typical values are for uncompacted, drained material at rest. Vibration, moisture, surcharge, and particle shape all affect the stable angle.

Limitations

Lookup values are approximate and vary with moisture content, particle shape, grading, and degree of compaction.

The angle of repose applies to loose, unconsolidated material only. It is not the same as the angle of internal friction (φ’) used in geotechnical design.

Revision history

30 June 2026: Initial release

Disclaimer

This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.

Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.

All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.

By using this tool, you accept full responsibility for how you interpret and apply the information provided.

Spotted an error? Let us know.

Input method

Pile height (m)

Base radius (m)

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