Beer-Lambert law calculator
Absorbance is proportional to concentration and path length, which is what makes a spectrophotometer a quantitative instrument.
L/(mol cm)
mol/L
cm
Absorbance
0.6220
- Transmittance
- 23.878 %
Show the working
- Molar absorptivity = 6220
- Concentration = 0.0001
- Path length = 1
- Absorbance = 6220 * 0.0001 * 1 = 0.622
- Transmittance = 10^(-0.622) * 100 = 23.8781
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- A = epsilon x c x l
- %T = 100 x 10^-A
The linear relation fails above about A = 1.5 on most instruments, and in solutions concentrated enough for the molecules to interact.
The default molar absorptivity, 6220 L/(mol cm), is NADH at 340 nm.