Physics
Wavelength from speed and frequency
The same relationship solved for wavelength. Use it when the medium is known and only the frequency is chosen.
The Formula
lambda = v / f
The same relationship solved for wavelength. Use it when the medium is known and only the frequency is chosen.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| v | Wave speed | metres per second | Set by the medium and its temperature; 343 m/s for air at 20 degrees Celsius. |
| f | Frequency of the wave | hertz | In hertz. Dividing the fixed speed by it gives the required wavelength. |
| lambda | Wavelength | metres | At 1000 Hz in air this is 0.343 metres, half the wavelength of a 500 Hz tone. |
What Each Symbol Means
vmetres per second
Wave speed
Set by the medium and its temperature; 343 m/s for air at 20 degrees Celsius.
fhertz
Frequency of the wave
In hertz. Dividing the fixed speed by it gives the required wavelength.
lambdametres
Wavelength
At 1000 Hz in air this is 0.343 metres, half the wavelength of a 500 Hz tone.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate wave speed page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Wave Speed, filed under Science. Every number the guide produces comes from substituting into this one line.