Wavelength Calculator – Frequency to Wavelength
This wavelength calculator converts between frequency and wavelength using ฮป = v ÷ f. Choose the wave speed: the speed of light for radio, Wi-Fi, microwaves and visible light, the speed of sound in air at 68 °F, sound in water, or any custom speed. Enter a frequency in Hz, kHz, MHz, GHz or THz to get the wavelength in meters, centimeters, millimeters, nanometers, feet and inches, or enter a wavelength to get the frequency. For light it also shows photon energy in electron-volts and the color band. It is great for physics class, ham radio antennas and audio work.
Wavelength Calculator
Convert between wavelength and frequency for light, radio or sound.
How to use the Wavelength Calculator
- Pick the kind of wave, which sets the speed.
- Choose frequency to wavelength, or the reverse.
- Enter the value and unit.
- Read the result in several units.
Wave formula
ฮป = v ÷ f and f = v ÷ ฮป. Photon energy E = h × f, with h = 6.626 × 10^-34 J·s.
Features
- Frequency to wavelength and back
- Light, sound in air, sound in water or custom speed
- Hz to THz and nm to feet
- Photon energy in eV
- Color band for visible light
- Copy and print
Frequently asked questions
What is the wavelength formula?
Wavelength ฮป = wave speed ÷ frequency. For light, ฮป = 299,792,458 m/s ÷ f.
What is the wavelength of a 2.4 GHz Wi-Fi signal?
About 12.5 cm, or 4.9 inches.
What is the wavelength of a 440 Hz sound in air?
At 68 °F the speed of sound is about 343 m/s, so the wavelength is about 0.78 m (2.56 ft).
How do I find frequency from wavelength?
Frequency f = wave speed ÷ wavelength. Green light at 532 nm is about 563 THz.
What is photon energy?
E = h × f, where h is the Planck constant. Visible light photons carry about 1.6 to 3.3 electron-volts.