Beer-Lambert Concentration
Concentration from absorbance, path length, and molar extinction coefficient.
Example
You enter
- Absorbance (AU) 1
- Path length (cm) 1
- Molar extinction coefficient (M^-1 cm^-1) 10000
You get
- Concentration 0.0001 M
Checked against published worked examples from: LibreTexts Chemistry; LibreTexts Chemistry (David Harvey, DePauw University).
Details, formula, and sources
Formula or tableA = epsilon * c * L => c = A / (epsilon * L). Path length in cm; epsilon in M^-1 cm^-1; concentration returned in M.
Source and editionBeer-Lambert law. First principles.
Free accessNo code citation required (physical chemistry).
What governsVerify protocol against your lab's SOP before pipetting. A miscalculated dilution can ruin a run or a sample.
API field namesabsorbance, path_length_cm, epsilon, concentration
- Linear range A in 0.1-1.0 typical; deviations at high concentration outside this rangespectrophotometry convention