Frequency Converter

A Hertz (Hz) is the SI unit of frequency, equal to one cycle per second. It is named after physicist Heinrich Hertz who first proved the existence of electromagnetic waves.

1 Hz = 60 RPM because one revolution per minute is one cycle every 60 seconds. To convert RPM to Hz, divide by 60. For example, a motor at 3,000 RPM spins at 50 Hz.

Frequency (f) in Hz counts complete cycles per second. Angular frequency (omega) in radians/sec measures the rate of change of angle. They are related by omega = 2 x pi x f.

Visible light spans roughly 430 THz (red, ~700 nm) to 750 THz (violet, ~400 nm). These are electromagnetic waves at terahertz frequencies.

Modern CPUs run at 3–5 GHz (gigahertz), meaning they can execute billions of cycles per second. This is equivalent to 3,000–5,000 MHz or 3–5 x 10^9 Hz.

In North America the AC power grid runs at 60 Hz. In Europe, Asia, and most of the rest of the world it runs at 50 Hz. This affects motor speeds and some electronics.