Frequency Converter: Convert Hz, kHz, MHz, GHz Instantly

Frequency counts how many cycles of a repeating event happen each second, and the unit is the hertz: 1 hertz is 1 cycle per second. A 50 hertz mains supply alternates 50 times a second, a 440 hertz tuning fork vibrates 440 times a second, and an FM radio station at 100 megahertz oscillates 100 million times a second.

The prefixes scale by thousands: 1 kilohertz is 1,000 hertz, 1 megahertz is 1,000,000, 1 gigahertz is 1,000,000,000, and 1 terahertz is 1,000,000,000,000. Converting is just moving the decimal point by groups of three, which is why the factors look large but the arithmetic stays simple.

For time units rather than cycles, a time converter handles seconds, minutes, and hours, while this converter stays with cycles per second.

Period is the time one cycle takes, and it is the reciprocal of frequency: period equals 1 divided by frequency. A 100 hertz wave has a period of 0.01 seconds, or 10 milliseconds, while a 2.4 gigahertz Wi-Fi signal has a period of about 0.42 nanoseconds.

Angular frequency, written omega, is 2 times pi times frequency, in radians per second. It appears in wave and rotation math, where angles are measured in radians rather than cycles: 100 hertz is about 628 radians per second.

Example 1: 100 megahertz to kilohertz. 100 megahertz is 100,000,000 hertz, divided by 1,000 gives 100,000 kilohertz. Example 2: 2.4 gigahertz to megahertz: 2,400 megahertz. Example 3: 440 hertz to kilohertz: 0.44 kilohertz, with a period of about 0.00227 seconds.

Example 4: 60 hertz mains to period: 1 divided by 60 is 0.01667 seconds, or 16.67 milliseconds per cycle. That is why mains hum and flicker sit near 50 or 60 hertz depending on the country.

Mains electricity runs at 50 hertz in most of the world and 60 hertz in North America. Human hearing spans roughly 20 hertz to 20 kilohertz. FM radio sits between 88 and 108 megahertz, Wi-Fi uses 2.4 and 5 gigahertz bands, and computer processors run at several gigahertz, meaning billions of cycles per second.

Light is also a frequency, but far higher: visible light spans about 430 to 770 terahertz, which is why terahertz appears in optics even though it rarely appears in audio or radio work.

The most common mistake is mixing up kilohertz and megahertz by a factor of 1,000: 100 megahertz is 100,000 kilohertz, not 100. A second mistake is treating frequency and period as the same thing: frequency counts cycles per second, period measures seconds per cycle, and they are reciprocals, not equals.

A third mistake is confusing frequency with wavelength: higher frequency means shorter wavelength for the same wave speed, since wavelength equals speed divided by frequency. For radio waves, speed is the speed of light, about 300 million meters per second.

Frequency conversion matters in electronics, radio, audio, and computing: matching a radio to a station, checking a processor clock, setting an oscillator, or reading a spectrum analyzer all need clean unit changes. Audio engineers live in hertz and kilohertz, radio engineers in megahertz and gigahertz.

Period matters wherever timing is critical: a 1 kilohertz control loop has 1 millisecond per cycle to do its work, and a 60 hertz display refreshes every 16.67 milliseconds. Knowing both forms of the same number avoids timing errors that are hard to debug later.