How to Convert Frequencies

Frequency measurements commonly occur in engineering and the physical sciences. A frequency value indicates how often a repeating event takes place. In scientific contexts, though, frequencies are typically used to describe waves, such as sound waves, light waves or electrical waves. The fundamental unit of frequency is the hertz (abbreviated Hz), which is sometimes known as "cycles per second." If a wave repeats itself once in a second, it has a frequency of 1 Hz. Certain situations, however, are easier to analyze if the frequency is expressed in different units or as a different (but related) quantity.
1
Multiply the frequency by 2 x pi (approximately 6.28) to convert frequency convert to angular frequency. Angular frequency has a unit of radians per second instead of cycles per second. In angular motion, one full cycle corresponds to 2pi radians (or 360 degrees), so angular frequency more clearly describes the rotational motion of an object.
2
Divide 1 by the frequency to determine the period. This is called taking the "inverse" of the frequency. Whereas frequency tells you how many times an event happens in a second, the period tells you how long it takes to complete one event. The unit for period is seconds per cycle, usually shortened to just seconds. Period measurements are common in electronics because the period of a timing signal determines how long the device will operate in a certain way.
3
Divide the velocity of a wave by the frequency to determine the wavelength. Wavelengths are often used to describe electromagnetic waves -- like light-- in which case the formula becomes: wavelength = (speed of light) / (frequency). The wavelength tells you the physical distance between the beginning of one cycle and the beginning of the previous cycle.
4
Multiply the frequency by 60 to express the frequency in revolutions per minute (or RPM). Since there are 60 seconds in a minute, if a device completes 60 revolutions in one minute, it completes one revolution in one second, so 1 cycle per second = 60 revolutions per minute. The rotational motion of mechanical devices is commonly expressed in RPM.