Universal wave equation

The universal wave equation is

v=fλ.

propagation speed (v)
the speed of the wave, measured in metres per second (m/s)
frequency (f)
the number of cycles completed in one second, measured in hertz (Hz)
wavelength (λ)
the length of one cycle in the wave, measured in metres (m)

We also have a few other equations for dealing with period:

f=NΔt, T=ΔtN, f=1T.

number of cycles (N)
the number of cycles completed during a time interval (unitless)
time interval (Δt)
a specific duration of time, measured in seconds (s)
period (T)
the time it takes for one cycle to be completed, measured in seconds (s); wavelength is the spatial length, period is the temporal length