USCS Soil Classification Calculator

The ASTM D2487 soil classification system, an ASTM adaptation of the Unified Soil Classification System (USCS), categorizes mineral and organo-mineral soils for engineering purposes based on particle-size distribution, liquid limit, and plasticity index. This widely used soil classification system helps geotechnical engineers, laboratories, and construction professionals consistently classify soils for design, testing, and reporting.

This USCS Calculator functions as a soil type calculator, allowing you to determine the appropriate soil group name and USCS symbols from your field data. It simplifies USCS soil classification for use in soil descriptions, geotechnical reports, boring logs, and test pit logs. For more information, you can refer to the official USCS guidelines.

What is the USCS Soil Classification Calculator?

The USCS Soil Classification Calculator helps geotechnical engineers, construction materials testing laboratories, and field technicians classify soil according to the Unified Soil Classification System (USCS). By entering the particle size distribution and Atterberg Limits, the calculator determines the appropriate soil group in accordance with ASTM D2487. This USCS calculator simplifies the soil classification process and provides consistent results for engineering projects.

How does the Soil Classification System work?

The soil classification system groups soils based on grain size distribution and plasticity characteristics. The Unified Soil Classification System evaluates gravel, sand, fines content, liquid limit, and plasticity index to determine the appropriate soil group. Engineers commonly use this method during geotechnical investigations, foundation design, and construction quality control.

Understanding USCS Symbols

The calculator returns standard USCS symbols that identify soil groups. Common examples include:

Gravels

• GW – Well-graded gravel
• GP – Poorly graded gravel

Sands

• SW – Well-graded sand
• SP – Poorly graded sand

Silts & Clays

• ML – Silt
• CL – Lean clay
• MH – Elastic silt
• CH – Fat clay