Wave Speed
Calculate wave speed from frequency and wavelength using the wave equation v = f × λ. Free online physics calculator for sound, light, and mechanical waves with charts and breakdowns.
About This Calculator
The Wave Speed Calculator computes how fast a wave propagates through a medium using the fundamental wave equation v = f × λ, where v is the wave speed in meters per second (m/s), f is the frequency in Hertz (Hz), and λ is the wavelength in meters (m). This calculator is designed for students, educators, and professionals working with waves in physics, acoustics, optics, and telecommunications.
Wave speed, also called wave velocity or phase velocity, is the speed at which a wave crest travels through a medium. It depends on the properties of the medium (such as density and elasticity) and the type of wave. For electromagnetic waves like light, the speed in a vacuum is a universal constant (c ≈ 3 × 10⁸ m/s). The calculator also computes the wave period T = 1/f (time for one complete cycle) and the wavenumber k = 1/λ (spatial frequency of the wave).
How to Use
Enter the wave frequency and wavelength into the input fields. The calculator instantly computes the wave speed using the formula v = f × λ. A breakdown table shows each component of the calculation, and interactive charts visualize the relationship between frequency, wavelength, wave speed, period, and wavenumber. You can share your results via a URL that preserves all input values.
Frequently Asked Questions
What is the wave speed formula?
Wave speed is calculated using the formula v = f × λ, where v is the wave speed in meters per second (m/s), f is the frequency in Hertz (Hz), and λ is the wavelength in meters (m).
How do I calculate wave speed from frequency and wavelength?
Enter the wave frequency in Hertz (Hz) and the wavelength in meters (m), then click Calculate. The calculator multiplies the frequency by the wavelength to give you the wave speed in meters per second (m/s), along with the wave period and wavenumber.
What is the difference between wave speed and wave velocity?
Wave speed and wave velocity are often used interchangeably in physics. Both refer to the speed at which a wave propagates through a medium, calculated using v = f × λ. Velocity may additionally specify direction, while speed is the scalar magnitude.
How do I calculate the period of a wave?
The period T of a wave is the reciprocal of its frequency: T = 1/f. For example, if the frequency is 10 Hz, the period is 0.1 seconds. The calculator provides the period alongside the wave speed.
What is the wave speed of light in a vacuum?
The speed of light in a vacuum is approximately 299,792,458 meters per second (m/s). This universal constant, denoted as c, is the maximum speed at which all energy, matter, and information can travel.
How fast does sound travel through air?
The speed of sound in dry air at 20 °C is approximately 343 meters per second (m/s). Sound travels faster in warmer air and in denser media like water (about 1,480 m/s) and steel (about 5,960 m/s).
What is the relationship between wave speed, frequency, and wavelength?
Wave speed equals the product of frequency and wavelength (v = f × λ). For a given wave speed, a higher frequency means a shorter wavelength, and vice versa. This inverse relationship is fundamental to wave physics.
What units does the wave speed calculator use?
The calculator uses Hertz (Hz) for frequency, meters (m) for wavelength, meters per second (m/s) for wave speed, seconds (s) for period, and reciprocal meters (1/m) for wavenumber. These are the standard SI units for wave measurements.