Wavelength & Frequency Calculator
Calculate wave speed, wavelength, frequency, photon energy and period · EM spectrum · Sound waves
Show calculation steps
- λ = v / f
- λ = 500.00 THz → v=299792458 m/s
- λ = 599.58 nm
What is Wavelength & Frequency Calculator?
A wavelength and frequency calculator is a physics tool that computes the relationship between wavelength, frequency, wave speed, period, and photon energy for any electromagnetic or mechanical wave. The fundamental equation linking these quantities is the wave equation: wave speed equals frequency multiplied by wavelength (v = f * λ).
For electromagnetic waves traveling through a vacuum, the wave speed is the speed of light (approximately 299,792,458 metres per second). This means you can calculate the wavelength of any radio wave, microwave, infrared, visible light, ultraviolet, X-ray, or gamma ray by entering its frequency, and vice versa. The tool also calculates photon energy using Planck's equation (E = h * f), where h is Planck's constant.
An interactive electromagnetic spectrum diagram helps you visualise where your calculated frequency or wavelength falls — whether it is an AM radio broadcast, a Wi-Fi signal, the red end of the visible spectrum, or a high-energy gamma ray. This makes the tool especially useful for students and educators in physics and chemistry.
The calculator supports a wide range of unit prefixes (Hz, kHz, MHz, GHz, THz and nm, μm, mm, cm, m) so you can work comfortably with values at any scale. It is useful for telecommunications engineering, optics, spectroscopy, antenna design, and physics coursework.
How to Use Wavelength & Frequency Calculator
- Choose what you know
Select whether you are starting from frequency, wavelength, or wave speed. Enter your known value and choose the unit.
- Calculate instantly
The tool computes all related quantities — wavelength, frequency, period, and photon energy — simultaneously.
- Explore the EM spectrum
See where your wave falls on the interactive electromagnetic spectrum diagram, from radio waves to gamma rays.
- Read and copy results
Copy any result value in your preferred unit for use in reports, homework, or engineering calculations.
Key Benefits
Enter one value and get wavelength, frequency, period, and photon energy all at once — no manual formula lookup needed.
An interactive spectrum diagram puts your result in context, showing which part of the electromagnetic spectrum it occupies.
Works with Hz through THz for frequency and nm through km for wavelength — covers the full practical range.
Calculates photon energy in joules and electron-volts using Planck's constant, useful for quantum physics problems.
Frequently Asked Questions
Frequency and wavelength are inversely proportional for a given wave speed. As frequency increases, wavelength decreases. The relationship is: wavelength = wave speed divided by frequency.
For EM waves in a vacuum, the calculator uses the speed of light: 299,792,458 m/s (approximately 3 x 10^8 m/s). For mechanical waves, you can enter a custom wave speed.
Photon energy is the energy carried by a single photon of light. It is calculated using E = h * f, where h is Planck's constant (6.626 x 10^-34 J·s) and f is the frequency.
Yes. Switch to custom wave speed mode and enter the speed of sound in your medium (approximately 343 m/s in air at 20°C) to calculate acoustic wavelength and frequency.