Geotechnical Toolbox has a new address: "geotechsuite.com". The old address will work until Dec 31, 2026. If you have bookmarked the old address, please update it.Open New Address
Geotechnical Toolbox

Soil Mechanics & Lab Tests

Atterberg Limits & Flow Curve Plotter

Plot the liquid limit flow curve (moisture content vs. number of blows on a semi-log scale) to automate the interpolation of the Liquid Limit, Plasticity Index, and Liquidity Index.

ASTM D4318

Inputs

Demo

Flow Curve Data

Blows (N)
Moisture (%)
Action

Additional Limits (Optional)

Required to calculate Plasticity Index (PI)

Required to calculate Liquidity Index (LI)

Results

Results

Enter at least 2 valid data points to see the results and flow curve.

Theory and formulae

Atterberg Limits Formulations

About this calculator

This free atterberg limits calculator runs entirely in your browser: what you enter is never uploaded. Use the calculation steps and the theory section to check the working, and print a calculation sheet with the inputs, results and formulae for your records.

Methods and references: ASTM D4318.

Topics: atterberg limits, liquid limit, plastic limit, plasticity index, liquidity index, flow curve, casagrande.

Engineering notice: Results are for preliminary estimation, screening and education. All inputs and outputs must be independently verified by a qualified professional engineer before use in any design or construction decision. Read the full disclaimer