USCS Soil Classifier | Geotechnical Tools

Enter the soil properties below to classify according to the Unified Soil Classification System (ASTM D2487).

1. Soil composition (must sum to 100%)

Gravel, retained No. 4 (%)

Sand, passing No. 4 / retained No. 200 (%)

Fines, passing No. 200 (%)

2. Gradation parameters (coarse soils)

Coefficient of uniformity, C_u

Coefficient of curvature, C_c

3. Atterberg limits (fine and plastic soils)

Liquid limit, LL (%)

Plastic limit, PL (%)

Liquid limit after oven drying (%)

4. Modifiers

Contains cobbles

Contains boulders

Verify Atterberg limits against the U-line

5. Missing-data fallbacks

Optional assumptions applied only when the corresponding laboratory data is unavailable.

Assume organic when organic content > 5% (if oven-dry LL is missing)

Organic content (%)

Assume non-plastic (M) for coarse soils when LL/PL are missing

Assume non-plastic (ML) for fine soils when LL/PL are missing

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