Analyze absorbance, transmittance, concentration, and photon energy. Convert wavelength values into practical chemistry insights today. Save neat outputs for classwork, lab notes, and revision.
| Sample | λmax (nm) | ε (L·mol⁻¹·cm⁻¹) | Path length (cm) | Concentration (mol/L) | Estimated A |
|---|---|---|---|---|---|
| Caffeine standard | 272 | 12400 | 1.0 | 1.50e-5 | 0.186 |
| Benzene reference | 254 | 230 | 1.0 | 4.00e-3 | 0.920 |
| Nitrate sample | 220 | 7100 | 1.0 | 2.00e-5 | 0.142 |
| Acetophenone check | 244 | 12800 | 1.0 | 5.00e-5 | 0.640 |
Beer-Lambert law: A = ε × c × l
Absorbance from transmittance: A = -log10(T / 100)
Transmittance from absorbance: T% = 10-A × 100
Wavenumber: ṽ = 107 / λ(nm)
Frequency: ν = c / λ
Photon energy: E = h × c / λ
Electron volt conversion: E(eV) = 1240 / λ(nm)
A UV spectrum calculator helps convert raw wavelength and absorbance inputs into useful analytical chemistry values. This page estimates transmittance, photon energy, wavenumber, frequency, concentration, and molar absorptivity. It supports Beer-Lambert calculations for routine lab work. It also helps students review core spectroscopy relationships. You can test a measured absorbance, predict a concentration, or examine how wavelength changes the energy of absorbed radiation. This makes the tool practical for method development, classroom problems, sample screening, and report preparation. It also supports blank checks and sensible concentration reporting for routine labs.
Wavelength controls the energy carried by light. Shorter wavelengths carry more energy. Longer wavelengths carry less. In ultraviolet spectroscopy, many compounds show maximum absorbance at a specific wavelength. That point is often called lambda max. Choosing a suitable wavelength improves sensitivity and selectivity. It can reduce noise from solvents, impurities, and weak bands. The calculator therefore converts nanometers into electron volts, joules, frequency, and wavenumber. These linked outputs help explain spectral behavior and support better interpretation of peaks, shifts, and intensity changes.
The Beer-Lambert law connects absorbance with concentration, path length, and molar absorptivity. When two of those variables are known, the third can usually be estimated. That is useful in assay work, kinetics, environmental testing, and quality control. If absorbance is too high, the solution may need dilution. If absorbance is too low, sensitivity may suffer. This calculator highlights those relationships quickly. It also converts absorbance into transmittance, which is still common in older instruments and teaching labs. That saves time during manual checking.
This UV spectrum calculator suits chemistry students, lab analysts, tutors, and technical writers. It is helpful for quick checks before running standards or writing conclusions. You can export results for clean documentation. The example table shows how typical sample values look in practice. Use the formula section to understand the math. Use the instructions section to run the tool correctly. With one page, you can move from wavelength data to meaningful UV spectroscopy insight without opening multiple references or performing repeated hand calculations.
It estimates absorbance, transmittance, concentration, molar absorptivity, photon energy, frequency, and wavenumber from the values you provide.
No. The calculator works with partial inputs. Wavelength is required, then other values are used to derive missing Beer-Lambert variables whenever possible.
Molar absorptivity, often written as ε, measures how strongly a compound absorbs light at a specific wavelength in a 1 cm cell.
Very high absorbance can reduce linear accuracy. Many UV methods work best in a moderate absorbance range, so dilution may be necessary.
Use the optical path length of your cuvette or cell. A standard UV cuvette is often 1 cm, but other lengths are also valid.
Yes. Enter transmittance in percent. The calculator applies A = -log10(T/100) and returns the corresponding absorbance value.
It corrects the derived concentration back to the original sample level when your measured solution was diluted before scanning.
Yes. After calculation, use the CSV button for spreadsheet export or the PDF button for a clean shareable result file.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.