Wavelength to Frequency Converter

Convert between wavelength and frequency for electromagnetic waves. Supports metric units from picometers to meters and Hz to THz.

Wavelength → Frequency
Frequency → Wavelength
nm
Enter the wavelength value
Select the unit of the input value
500 nm (visible)
1 μm (IR)
10 cm (microwave)
100 MHz (FM radio)
2.4 GHz (WiFi)
500 THz (visible)
Conversion Result
500 nm = 599.58 THz
Input Value
500 nm
Wavelength nm
Converted Value
599.58 THz
Frequency
Equivalent Values in Different Units
500
nm
0.5
μm
5e-7
m
599.58
THz

Understanding Wavelength and Frequency

Wavelength (λ) and frequency (f) are fundamental properties of waves. For electromagnetic waves, they are related by the speed of light: c = λ · f, where c = 299,792,458 m/s (approximately 3×10⁸ m/s).

Key Formulas:

f (Hz) = c / λ (m)

λ (m) = c / f (Hz)

c = 299,792,458 m/s (exact)

Electromagnetic Spectrum

Band Wavelength Range Frequency Range Common Applications
Gamma rays < 10 pm > 30 EHz Medical imaging, astronomy
X-rays 10 pm – 10 nm 30 PHz – 30 EHz Medical diagnostics, crystallography
Ultraviolet 10 nm – 400 nm 750 THz – 30 PHz Sterilization, fluorescence
Visible light 400 nm – 700 nm 430 THz – 750 THz Human vision, optics
Infrared 700 nm – 1 mm 300 GHz – 430 THz Thermal imaging, remote controls
Microwaves 1 mm – 1 m 300 MHz – 300 GHz WiFi, radar, microwave ovens
Radio waves 1 m – 100,000 km 3 Hz – 300 MHz Broadcasting, communication

Practical Applications

1

Telecommunications: Antenna design requires converting frequency to wavelength to determine optimal antenna length (dipole antennas are typically half-wavelength).

2

Spectroscopy: Identifying materials by analyzing the wavelength of absorbed or emitted light. Wavelength is often converted to frequency or wavenumber.

3

Astronomy: Doppler shift measurements use wavelength/frequency conversions to determine the velocity of stars and galaxies.

Common Conversion Examples

Wavelength Frequency Wave Type
500 nm (green light) 599.6 THz Visible
10 μm 30.0 THz Infrared (thermal)
1 mm 299.8 GHz Microwave
1 m 299.8 MHz Radio (FM band)
100 MHz 3.0 m Radio (VHF)
2.4 GHz 12.5 cm WiFi

Calculator Features:

  • Converts between wavelength and frequency using exact speed of light
  • Supports 7 wavelength units (m to pm) and 5 frequency units (Hz to THz)
  • Real-time calculation with immediate results
  • Shows equivalent values in all common units
  • Includes typical examples for radio, microwave, infrared, visible light

Frequently Asked Questions

The speed of light in vacuum is defined as exactly 299,792,458 meters per second. This definition fixes the meter as the distance light travels in 1/299,792,458 seconds. It's a fundamental constant of nature.

First convert nm to meters (1 nm = 10⁻⁹ m). Then use f = c / λ. For example, 500 nm = 5×10⁻⁷ m, so f = 3×10⁸ / 5×10⁻⁷ = 6×10¹⁴ Hz = 600 THz (approximately). Use our calculator for exact values.

Yes, the speed of light is slower in a medium (c/n, where n is refractive index). This calculator uses vacuum speed. For accurate conversion in other media, you'd need to adjust the speed. However, frequency remains constant, wavelength changes.

Wavenumber (cm⁻¹) is the reciprocal of wavelength in centimeters: ν̃ = 1/λ(cm). It's commonly used in infrared spectroscopy. To convert wavelength in nm to cm⁻¹, first convert to cm (divide by 10⁷), then take reciprocal.

The approximation is accurate to about 0.07%. For most engineering purposes it's fine, but our calculator uses the exact value for precision.