⛏️ USCS Soil Classifier

ASTM D2487 Unified Soil Classification System. Input sieve analysis results and Atterberg limits to determine USCS group symbol and engineering properties.

Sieve Analysis

% Passing No. 4 Sieve (4.75 mm)

Separates gravel from sand

% Passing No. 40 Sieve (0.425 mm)

Needed for Atterberg limit sample

% Passing No. 200 Sieve (0.075 mm)

Coarse vs. fine-grained threshold

Atterberg Limits (fine-grained soils)

Liquid Limit (LL)

Plastic Limit (PL)

Plasticity Index (PI)—

Suspected Organic Soil

Dark color, organic odor, plant fibers visible

🪨

Enter soil data and click Classify

USCS group symbol and engineering property estimates will appear here.

Quick Reference: Fines Threshold

• <5% passing #200 — Coarse, clean (GW/GP/SW/SP)

• 5–12% passing #200 — Borderline, dual symbol

• >12% passing #200 — Coarse with fines (GM/GC/SM/SC)

• ≥50% passing #200 — Fine-grained (ML/CL/MH/CH)