Calculator Inputs
This page stays single-column overall, while the calculator fields shift to three columns on large screens, two on medium screens, and one on mobile.
Example Data Table
These sample wavelengths show how photon energy and molar energy change across common chemistry and spectroscopy ranges.
| Wavelength (nm) | Photon Energy (eV) | Molar Energy (kJ/mol) | Spectral Band |
|---|---|---|---|
| 254 | 4.8813 | 470.97 | Ultraviolet |
| 405 | 3.0613 | 295.37 | Visible light |
| 532 | 2.3305 | 224.86 | Visible light |
| 650 | 1.9074 | 184.04 | Visible light |
| 1064 | 1.1653 | 112.43 | Infrared |
Formula Used
Photon energy: E = h × c / λ
Frequency: ν = c / λ
Wavenumber: ṽ = 1 / λ
Momentum: p = h / λ
Molar energy: Emolar = E × NA
Medium wavelength: λmedium = λvacuum / n
Constants used: Planck’s constant, light speed, Avogadro’s number, and elementary charge.
All outputs come from one internally consistent vacuum wavelength value.
How to Use This Calculator
- Choose whether your known value is a wavelength, frequency, energy, or wavenumber.
- Enter the numeric value and then select the matching unit.
- Set refractive index if you want the wavelength inside a medium.
- Pick the number of decimal places for your preferred display precision.
- Press Convert Now to show results above the form.
- Review the detailed output table, chemistry band label, and graph.
- Use the CSV or PDF buttons to export your current calculation.
FAQs
1) What does this converter calculate?
It converts among wavelength, frequency, photon energy, molar energy, wavenumber, and momentum. It also labels the spectral region and shows how wavelength changes in a medium.
2) Why is refractive index included?
Refractive index changes the wavelength inside a material. Frequency and photon energy remain the same, but the medium wavelength becomes shorter as refractive index increases.
3) What is the difference between photon energy and molar energy?
Photon energy describes one photon. Molar energy scales that value to one mole of photons using Avogadro’s number, which is useful in chemistry and photochemistry.
4) What is wavenumber in chemistry?
Wavenumber is the reciprocal of wavelength, usually written in cm⁻¹. It is heavily used in infrared, Raman, and molecular spectroscopy because it directly tracks energy spacing.
5) Can I use visible, ultraviolet, and infrared values?
Yes. The calculator accepts very small and very large wavelengths, then classifies the result into gamma, X-ray, ultraviolet, visible, infrared, microwave, or radio ranges.
6) Why does the graph slope downward?
Photon energy is inversely proportional to wavelength. As wavelength increases, energy decreases, so the energy-versus-wavelength curve naturally falls from left to right.
7) Which wavelength should I enter for solution measurements?
Most instruments report wavelength in air or vacuum-equivalent terms. If you need the wavelength inside a medium, enter refractive index so the calculator also shows the medium value.
8) When should I export CSV or PDF?
Use CSV when you want spreadsheet-ready data. Use PDF when you need a clean report for class notes, lab records, documentation, or client-facing summaries.