Wavelength converter

What it means

What color is that?

Wavelengths are for a vacuum. In glass or water light slows down and the wavelength shortens, while the frequency stays put.

Every unit

Your light in every unit

• Nanometers550 nm
• Micrometers0.55 µm
• Ångströms5,500 Å
• Meters5.5×10⁻⁷ m
• Terahertz545.1 THz
• Gigahertz545,077.2 GHz
• Electronvolts2.254 eV
• Wavenumbers18,181.82 cm⁻¹

Learn

Three things worth knowing

• 💡

  1240 divided by nanometers gives electronvolts

  Green light at 550 nm is 2.25 eV. Blue is more energetic than red, which is why blue light does the damage and red does not.

• 📜

  Ångström, before nanometers

  Anders Ångström mapped the solar spectrum in units of 10⁻¹⁰ m. Spectroscopists still quote ångströms, which are simply tenths of a nanometer.

• ⚠️

  Wavelength changes in glass, frequency does not

  Light entering glass slows and its wavelength shrinks by the refractive index, but the color you see is unchanged, because frequency is what the eye responds to.

Shortcuts

Popular wavelength conversions

• nm → THz
• THz → nm
• nm → eV
• eV → nm
• nm → µm
• nm → Å
• cm⁻¹ → nm
• µm → THz

Background

About light units