Beer Lambert Concentration Calculator
Calculate dilute-solution concentration, transmission and mass concentration from absorbance, molar absorptivity and path length.
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Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use decadic absorbance and convert the path to centimeters for the entered absorptivity convention.
A=ε lcm c; concentration=A/(ε lcm); transmittance=10^(−A)
Worked example
A=0.5, ε=10000 L/(mol cm) and 1 cm path give c=50 μmol/L. For molar mass 100 g/mol the mass concentration is 5 mg/L.
Assumptions and input details
Uniform monochromatic absorption with known absorptivity and corrected blank. Scattering, chemical equilibria, stray light, detector limits and actual analyte identity are not inferred. Values above ordinary linear instrument ranges are mathematical estimates.
References: IUPAC: Beer–Lambert law
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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