ToolsGeotechnicalGround Stress & Earth Pressure

Excavation Slope Calculator

Calculate excavation batter angle, slope ratio (V:H), and horizontal setback from depth. Includes common temporary works slope angles for different soil types.

Last updated 1 February 2026

About this tool

Calculate excavation batter angle, slope ratio, and horizontal setback for temporary excavations. Select from common preset angles or enter a custom value.

Enter the excavation depth to calculate the horizontal setback from the toe of the slope to the crest. This is essential for planning exclusion zones, plant positions, and adjacent structure protection.

Includes a reference table of common temporary excavation slopes for different soil types, from stiff clay (4V:1H) to very soft ground (1V:2H).

How to use this tool

1. Select a preset or enter a custom angle — presets cover common temporary works batters.

2. Enter the excavation depth — to calculate the horizontal setback distance.

3. Read the angle, slope ratio, and setback — use the setback to plan the excavation footprint.

Technical information

Setback = Depth / tan(angle) — horizontal distance from toe to crest

Slope ratio expressed as V:H (e.g. 1V:1H = 45°, 1V:2H = 26.6°, 2V:1H = 63.4°).

Limitations

The preset angles are indicative for temporary works only. Permanent slopes and excavations deeper than 1.2m in any soil type require a specific temporary works design per BS 6031 and CIRIA C760.

Actual safe batter angles depend on soil type, groundwater, surcharge loading, excavation duration, and adjacent structures. Always base the design on site-specific ground investigation.

This tool does not perform a slope stability analysis. For anything beyond simple shallow excavations, use a limit equilibrium or numerical analysis.

Revision history

1 February 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.

Common slope angles

Batter angle (°)

Angle from horizontal. 90° = vertical.

Excavation depth (m)

Optional — enter depth to calculate horizontal setback from the toe.

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