Science

Beer-Lambert Law Calculator

Absorbance, concentration and path length.

Enter your values

Results update instantly as you type — no submit needed.

Results
Concentration
7.3810e-5 M
In micromolar
73.81
Transmittance
23.99%
Absorbance
0.62

Quick answer

Absorbance is proportional to concentration and path length via molar absorptivity.

A = ε × l × c

How to use the Beer-Lambert Law Calculator

  1. 1Enter the measured absorbance.
  2. 2Enter molar absorptivity for the analyte and wavelength.
  3. 3Enter the cuvette path length.

Frequently asked questions

What absorbance range is reliable?

0.1–1.0 — outside that, detectors lose linearity.

Why is transmittance shown?

Some instruments report %T rather than absorbance.