Atterberg Limits Calculator

This calculator is designed for civil engineers and geotechnical professionals to accurately compute the Atterberg limits, crucial for soil classification and analysis. By entering the required soil parameters, users can quickly determine the liquid limit, plastic limit, and plasticity index.

Calculator

Liquid Limit (LL) *

Please enter a valid liquid limit.

Plastic Limit (PL) *

Please enter a valid plastic limit.

Results

Plasticity Index (PI): N/A

Data Source and Methodology

All calculations are based strictly on the formulas and data provided by the ASTM D4318 standard. View Source. All calculations are rigorously based on the formulas and data provided by this source.

The Formula Explained

The Plasticity Index (PI) is calculated using the formula:

\( PI = LL - PL \)

Glossary of Variables

Liquid Limit (LL): The moisture content at which soil changes from the plastic state to the liquid state.
Plastic Limit (PL): The moisture content at which soil changes from the semi-solid state to the plastic state.
Plasticity Index (PI): The numerical difference between the Liquid Limit and the Plastic Limit.

How It Works: A Step-by-Step Example

For example, if a soil sample has a Liquid Limit (LL) of 40% and a Plastic Limit (PL) of 20%, the Plasticity Index (PI) is calculated as follows:

PI = 40 - 20 = 20%

Frequently Asked Questions (FAQ)

What are Atterberg Limits?

Atterberg limits are the basic measures of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit.

Why are Atterberg Limits important?

They are used to distinguish between different types of soil and assess their suitability for construction and other purposes.

What is the Plasticity Index (PI)?

The Plasticity Index is the range of moisture content over which soil remains plastic.

How do I input data?

Enter the Liquid Limit and Plastic Limit values in the respective fields and click "Calculate" to get the Plasticity Index.

Can I use this calculator for all soil types?

This calculator is designed for fine-grained soils. It might not be suitable for soils with a high sand content.

```

Audit: Complete

Formula (LaTeX) + variables + units

This section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)

\[','\]

','

Variables and units

No variables provided in audit spec.

Sources (authoritative):

View Source — astm.org · Accessed 2026-01-19
https://www.astm.org/Standards/D4318.htm

Changelog

Version: 0.1.0-draft
Last code update: 2026-01-19

0.1.0-draft · 2026-01-19

Initial audit spec draft generated from HTML extraction (review required).
Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
Confirm sources are authoritative and relevant to the calculator methodology.

Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

, ', svg: { fontCache: 'global' } };

Atterberg Limits Calculator

Calculator

Liquid Limit (LL) *

Please enter a valid liquid limit.

Plastic Limit (PL) *

Please enter a valid plastic limit.

Results

Plasticity Index (PI): N/A

Data Source and Methodology

All calculations are based strictly on the formulas and data provided by the ASTM D4318 standard. View Source. All calculations are rigorously based on the formulas and data provided by this source.

The Formula Explained

The Plasticity Index (PI) is calculated using the formula:

\( PI = LL - PL \)

Glossary of Variables

Liquid Limit (LL): The moisture content at which soil changes from the plastic state to the liquid state.
Plastic Limit (PL): The moisture content at which soil changes from the semi-solid state to the plastic state.
Plasticity Index (PI): The numerical difference between the Liquid Limit and the Plastic Limit.

How It Works: A Step-by-Step Example

For example, if a soil sample has a Liquid Limit (LL) of 40% and a Plastic Limit (PL) of 20%, the Plasticity Index (PI) is calculated as follows:

PI = 40 - 20 = 20%

Frequently Asked Questions (FAQ)

What are Atterberg Limits?

Atterberg limits are the basic measures of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit.

Why are Atterberg Limits important?

They are used to distinguish between different types of soil and assess their suitability for construction and other purposes.

What is the Plasticity Index (PI)?

The Plasticity Index is the range of moisture content over which soil remains plastic.

How do I input data?

Enter the Liquid Limit and Plastic Limit values in the respective fields and click "Calculate" to get the Plasticity Index.

Can I use this calculator for all soil types?

This calculator is designed for fine-grained soils. It might not be suitable for soils with a high sand content.

```

Audit: Complete

Formula (LaTeX) + variables + units

This section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)

\[','\]

','

Variables and units

No variables provided in audit spec.

Sources (authoritative):

View Source — astm.org · Accessed 2026-01-19
https://www.astm.org/Standards/D4318.htm

Changelog

Version: 0.1.0-draft
Last code update: 2026-01-19

0.1.0-draft · 2026-01-19

Initial audit spec draft generated from HTML extraction (review required).
Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
Confirm sources are authoritative and relevant to the calculator methodology.

Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

]], displayMath: [['\\[','\\]']] }, svg: { fontCache: 'global' } };, svg: { fontCache: 'global' } };

Atterberg Limits Calculator

Calculator

Liquid Limit (LL) *

Please enter a valid liquid limit.

Plastic Limit (PL) *

Please enter a valid plastic limit.

Results

Plasticity Index (PI): N/A

Data Source and Methodology

All calculations are based strictly on the formulas and data provided by the ASTM D4318 standard. View Source. All calculations are rigorously based on the formulas and data provided by this source.

The Formula Explained

The Plasticity Index (PI) is calculated using the formula:

\( PI = LL - PL \)

Glossary of Variables

Liquid Limit (LL): The moisture content at which soil changes from the plastic state to the liquid state.
Plastic Limit (PL): The moisture content at which soil changes from the semi-solid state to the plastic state.
Plasticity Index (PI): The numerical difference between the Liquid Limit and the Plastic Limit.

How It Works: A Step-by-Step Example

For example, if a soil sample has a Liquid Limit (LL) of 40% and a Plastic Limit (PL) of 20%, the Plasticity Index (PI) is calculated as follows:

PI = 40 - 20 = 20%

Frequently Asked Questions (FAQ)

What are Atterberg Limits?

Atterberg limits are the basic measures of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit.

Why are Atterberg Limits important?

They are used to distinguish between different types of soil and assess their suitability for construction and other purposes.

What is the Plasticity Index (PI)?

The Plasticity Index is the range of moisture content over which soil remains plastic.

How do I input data?

Enter the Liquid Limit and Plastic Limit values in the respective fields and click "Calculate" to get the Plasticity Index.

Can I use this calculator for all soil types?

This calculator is designed for fine-grained soils. It might not be suitable for soils with a high sand content.

```

Audit: Complete

Formula (LaTeX) + variables + units

This section shows the formulas used by the calculator engine, plus variable definitions and units.

Formula (extracted LaTeX)

\[','\]

','

Variables and units

No variables provided in audit spec.

Sources (authoritative):

View Source — astm.org · Accessed 2026-01-19
https://www.astm.org/Standards/D4318.htm

Changelog

Version: 0.1.0-draft
Last code update: 2026-01-19

0.1.0-draft · 2026-01-19

Initial audit spec draft generated from HTML extraction (review required).
Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
Confirm sources are authoritative and relevant to the calculator methodology.

Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn