---
title: "Spectral / Energy Unit Converter calculator — AperiOptic"
description: "Enter a wavelength to see frequency, wavenumber, photon energy and equivalent kT temperature. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/spectral-energy-unit-converter"
---

# Spectral / Energy Unit Converter calculator

Enter a wavelength to see frequency, wavenumber, photon energy and equivalent kT temperature.

Category: [Unit Converters](https://aperioptic.com/calculators)

Formula: `E = hν = hc/λ = hc·ν̃`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Wavelength | `lam` | nm | 532 |

## Result with the default inputs

- λ: 532 nm
- λ: 0.532 µm
- ν: 563.5197 THz
- ν̃: 18796.9925 cm⁻¹
- E: 2.3305 eV
- E: 3.7339e-19 J
- E/k: 27044.6781 K

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/spectral-energy-unit-converter?lam=532`](https://aperioptic.com/calculators/spectral-energy-unit-converter?lam=532). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Photon energy](https://en.wikipedia.org/wiki/Photon_energy)

[All optics calculators](https://aperioptic.com/calculators)

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The interactive page: https://aperioptic.com/calculators/spectral-energy-unit-converter (AperiOptic runs in the browser; free, no account). Every page of the site as Markdown: https://aperioptic.com/llms.txt