f = v / λ
Where f is frequency, v is speed, λ (lambda) is wavelength.
For example, when sound travel in water, the speed is 1484 meters/sec, A Sound Wavelength of 23 Centimeters has a Frequency of 6.4522 KiloHertz. A Sound Frequency of 23 Hertz has a Wavelength of 64.522 Meters.