Wavelength Calculator

Yes. When light enters a medium with a higher refractive index (such as glass or water), its speed decreases, and since frequency remains constant, the wavelength shortens proportionally. For example, in water (n ≈ 1.33), the wavelength of green light (532 nm in vacuum) becomes approximately 400 nm.

The default velocity is c = 299,792,458 m/s, which is the exact speed of light in vacuum as defined by the SI system. You can modify this value in the advanced settings to calculate wavelengths in other media or for non-electromagnetic waves like sound.

The calculator automatically outputs wavelength in meters (m), nanometers (nm), and micrometers (μm). The conversions are: 1 m = 10⁹ nm = 10⁶ μm. For angstroms (Å), multiply nm by 10. For centimeters, divide meters by 100.

Yes. Change the wave velocity to the speed of sound in the medium of interest. For sound in air at 20°C, use approximately 343 m/s. For sound in water, use about 1,480 m/s. The formula λ = v/f applies universally to all wave phenomena.

The human eye can detect electromagnetic radiation with wavelengths from approximately 380 nm (violet) to 700 nm (red). Peak sensitivity occurs around 555 nm (green-yellow) under photopic (daylight) conditions. This narrow band represents less than 0.0035% of the entire electromagnetic spectrum.

Wavelength determines the type of molecular interaction that occurs. UV-Vis wavelengths (200–800 nm) excite electronic transitions, IR wavelengths (2.5–25 μm) excite vibrational modes, and microwave wavelengths (1 mm–1 m) excite rotational transitions. Identifying the correct wavelength range is essential for choosing the appropriate spectroscopic technique.

Photon energy is inversely proportional to wavelength: E = hc/λ, where h is Planck's constant (6.626 × 10⁻³⁴ J·s). Shorter wavelengths correspond to higher energies. A 200 nm UV photon has about 6.2 eV of energy, while a 700 nm red photon has only about 1.77 eV.

The calculator uses the exact value of c and performs IEEE 754 double-precision floating-point arithmetic, providing approximately 15–16 significant digits of precision. This exceeds the accuracy requirements of most spectroscopic instruments, which typically measure to 4–6 significant figures.

The de Broglie wavelength applies to matter particles: λ = h/(mv), where m is mass and v is velocity. This calculator is designed for classical waves (v = λf). For de Broglie wavelengths, you would need the particle mass and velocity rather than wave frequency.