What is the critical micelle concentration?

The CMC is the surfactant concentration above which molecules aggregate into micelles. Below the CMC, surface tension decreases as concentration rises; above it, surface tension stays roughly constant because additional surfactant goes into micelles rather than to the interface.

Why does CMC matter in formulation?

Working above the CMC ensures micelles are present to solubilize oils, deliver actives, or stabilize emulsions. Working far above the CMC wastes material without added benefit, so CMC sets the practical lower bound for effective surfactant use.

How does temperature affect CMC?

For ionic surfactants, CMC typically rises slightly with temperature. For nonionic ethoxylated surfactants, CMC can decrease with temperature because hydration of the ethylene oxide head groups weakens. Values in this database are at approximately 25 degrees Celsius.

How does salt affect CMC?

Added electrolyte screens the repulsion between charged head groups of ionic surfactants, lowering their CMC significantly. Nonionic surfactant CMC is much less sensitive to salt. The values shown here are for pure water.

What units are CMC values reported in?

CMC is most commonly reported in millimolar (mM) or in mass per volume (g/L or mg/L). This tool displays both mM and g/L columns. Values can span orders of magnitude: short-chain surfactants have CMC in the hundreds of mM while long-chain or gemini surfactants can be below 0.01 mM.

Are these values exact?

CMC values vary with purity, measurement technique, temperature, and ionic strength. The values here are representative literature values for research-grade surfactants in deionized water at 25 degrees Celsius. Use them for guidance and cross-check against your specific conditions.

Critical Micelle Concentration

Look up CMC values for common surfactants, compare them side by side, and understand micelle formation thresholds.

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CMC Checker

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CMC Reference Database

Surfactant	Abbreviation	Type	CMC (mM)	MW (g/mol)

Summary

The critical micelle concentration (CMC) is the minimum surfactant concentration at which micelles spontaneously form in solution. Below the CMC, surfactant molecules remain as monomers; above it, they self-assemble into aggregates that can solubilize hydrophobic compounds. This tool provides a reference database of CMC values for widely used anionic, cationic, nonionic, and zwitterionic surfactants, measured in water at approximately 25 degrees Celsius.

How it works

Search or browse surfactants by name or type using the filter controls.
Click any surfactant row to pin it to the comparison panel.
Compare up to four surfactants side by side in the comparison table.
Use the concentration input to see whether a given concentration is above or below the CMC.
Toggle between mM and g/L units with the unit selector.

Use cases

Formulating detergents, shampoos, or cleaning products at effective concentrations.
Designing drug-delivery systems that use micelles as carrier vehicles.
Selecting the right surfactant for emulsion polymerization.
Teaching or studying colloidal chemistry and self-assembly.
Comparing ionic vs nonionic surfactant behavior in solution.
Estimating the minimum surfactant dose needed for solubilization experiments.
Troubleshooting poor foam or wetting in industrial processes.
Cross-referencing literature CMC values in formulation research.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu