Enter the absorbance and molar concentration into the calculator to determine the molar extinction coefficient. This calculator can also evaluate the absorbance or molar concentration when given the other variable values.

Extinction Coefficient Formula

The following equation can be used to calculate a molar extinction coefficient.

E = A / mc
  • Where E is the extinction coefficient
  • A is the absorbance
  • mc is the molar concentration

To calculate an extinction coefficient, divide the absorbance by the molar concentration.

Extinction Coefficient Definition

The extinction coefficient is defined as the ratio of absorbance to the molar concentration of a solution.

Extinction Coefficient Example

How to calculate an extinction coefficient?

  1. First, determine the absorbance.

    Calculate the absorbance of the solution.

  2. Next, determine the molar concentration.

    Calculate the molar concentration of the substance.

  3. Finally, calculate the extinction coefficient.

    Calculate the coefficient of extinction using the equation above.


What is an extinction coefficient?

An extinction coefficient is a measure of a chemical’s ability to absorb light at a given wavelength.

What is absorbance?

Similarly, absorbance is also another measure of the substance’s ability to absorb light.