Some EM transmissions are made at millions of kHz. The kilohertz is a relatively small unit of frequency; more common units are the MHz, equal to 1,000,000 Hz or 1,000 kHz, and the GHz, equal to 1,000,000,000 Hz or 1,000,000 kHz. The kilohertz is often used to specify bandwidth for digital as well as analog signals.