Kilohertsi

Kilohertz, written as kHz, is a unit of frequency equal to 1,000 hertz, meaning 1,000 cycles per second. In the International System of Units (SI), hertz is the base unit for frequency, and the kilo- prefix denotes a factor of 10^3. Therefore, 1 kHz = 10^3 Hz and 1 Hz = 1 s^-1.

The term kilohertz uses the SI prefixes to form a decimal multiple of the hertz. The hertz is named after Heinrich Rudolf Hertz, a 19th-century German physicist who demonstrated radio waves. The form kilohertsi appears in some languages as an inflected variant, but in English the standard spellings are kilohertz and kHz.

Kilohertz is commonly used to describe frequencies in audio, radio, and certain timing and electronic contexts. In audio, audible sound spans roughly 20 Hz to 20 kHz, so many audio signals and equipment specifications are expressed in kilohertz. In radio communications, the kilohertz range covers portions of the low- and medium-frequency bands, from about 1 kHz up to several hundred kilohertz. In digital electronics and timing circuits, clock rates and sampling frequencies are frequently specified in kilohertz for lower-speed devices, while higher-performance systems use megahertz and gigahertz.

Examples include a 1 kHz tone, a 44.1 kHz sampling rate used in digital audio, and carrier frequencies described in the kilohertz region of the radio spectrum. Kilohertz is one of several SI-related frequency units, with common higher multiples such as megahertz (MHz) and gigahertz (GHz) used for increasingly faster phenomena.