Frequency Converter

Human hearing tops out around 20,000 Hz, an FM radio station broadcasts around 100,000,000 Hz, and a modern CPU core runs at several billion Hz. Frequency spans such an enormous range in daily technology that almost nobody writes it in plain hertz past the first few thousand.

Frequency unit conversions

What a hertz actually counts

One hertz means one complete cycle per second, named after Heinrich Hertz, who first demonstrated the existence of radio waves in the 1880s. It applies to anything that repeats: a sound wave vibrating the air, a radio signal oscillating, or a CPU clock ticking through instruction cycles.

The unit works identically whether you are describing something you can hear, something you tune a radio to, or something happening billions of times a second inside a silicon chip — only the scale of the prefix changes.

Frequency ranges worth knowing

• Human hearing: roughly 20 Hz to 20,000 Hz (20 kHz), and that upper limit drops noticeably with age.
• AM radio: 535 to 1,700 kHz.
• FM radio: 88 to 108 MHz.
• Wi-Fi: commonly 2.4 GHz and 5 GHz bands.
• Modern CPUs: typically 2 to 5 GHz per core, meaning billions of clock cycles every second.

The megahertz myth in computing

Through the 1990s and early 2000s, CPU marketing leaned heavily on clock speed alone, as if a higher MHz or GHz number always meant a faster chip. It was already misleading then, because architecture, instructions per cycle and core count matter enormously, and it became obviously false once manufacturers started shipping multi-core chips with lower individual clock speeds that comfortably outperformed older single-core chips running faster. Raw frequency is only one input to real-world performance, not the whole answer.

Frequency conversion questions