Wavelength Calculator
Solve for wavelength, velocity or frequency using the wave equation lambda equals v over f.
| Quantity | Value | Unit |
|---|
Reference velocity values for common waves
Reference velocity values help you choose the correct speed when calculating wavelength for sound or light traveling through different mediums.
| Wave type | Medium | Velocity |
|---|---|---|
| Speed of light | Vacuum | 299,792,458 m/s |
| Speed of sound | Air at 20°C | 343 m/s |
| Speed of sound | Water at 20°C | 1481 m/s |
The wavelength equation explained
The wavelength equation states that lambda equals v divided by f, where lambda represents wavelength, v represents wave velocity and f represents wave frequency. This relationship applies to all wave types including sound waves, light waves and radio waves.
Wavelength is calculated as the ratio of velocity to frequency. If you know any two of the three variables, this calculator solves for the third using one of the following rearranged formulas.
Solving for velocity
Solving for velocity requires multiplying wavelength by frequency, expressed as v equals lambda times f. This formula tells you how fast a wave is moving once you know its wavelength and frequency.
Solving for frequency
Solving for frequency requires dividing velocity by wavelength, expressed as f equals v divided by lambda. This formula determines how many wave cycles occur per second.
Worked example using a clocktower bell
Worked example calculations make the wavelength formula easier to apply in real situations. Consider a clocktower bell ringing at a frequency of 130 Hz while sound travels through air at 20°C, where the speed of sound is 343 meters per second.
Using lambda equals v divided by f, the calculation becomes 343 divided by 130, which equals approximately 2.64 meters. This means each wave crest of the bell tone is spaced about 2.64 meters apart as it travels through the air.
Frequently asked questions about wavelength
The wavelength formula is wavelength equals velocity divided by frequency, written as lambda equals v over f. This calculates the distance between two identical points on a wave.
To calculate wavelength from frequency, divide the wave velocity by the frequency value. For sound in air at 343 meters per second and a frequency of 130 Hz, the wavelength equals 2.64 meters.
The speed of sound in air at 20 degrees Celsius is 343 meters per second. The speed of sound in water at the same temperature is 1481 meters per second.
Frequency equals velocity divided by wavelength, written as f equals v over lambda. Divide the wave speed by the wavelength to get the frequency in hertz.
Standard units for wavelength calculations are meters for wavelength, meters per second for velocity and hertz for frequency. Other units such as feet, miles per hour and kilohertz are also supported and converted automatically.
The speed of light in a vacuum is 299792458 meters per second. This value is used when calculating the wavelength of electromagnetic waves such as light or radio signals.