Kilohertz to Millihertz (kHz to mHz)

1 kilohertz equals 1,000,000 millihertz exactly.

1 kilohertz = 1,000,000 millihertz

How to convert kilohertz to millihertz

To convert kilohertz to millihertz, multiply the number of kilohertz by 1,000,000. This factor is exact. To go the other way, multiply millihertz by 0.000001.

millihertz = kilohertz × 1,000,000

Example: 10 kilohertz = 10,000,000 millihertz.

About these units

Kilohertz (kHz)

Metric (SI)Current unit

1,000 hertz. AM radio stations are tuned in kilohertz and audio is sampled at 44.1 kHz.

Older radio operators called it the kilocycle. Before the CGPM adopted the hertz in 1960, thousands of cycles per second were written kc/s, and the popular press only switched to kilohertz in the late 1960s. The name changed, but the number on the dial did not.

A kilohertz is 1,000 hertz, a range that covers audible sound and medium-wave radio. Medium wave runs from 531 to 1602 kHz in Europe, Asia and Africa with 9 kHz channel spacing, and from 530 to 1700 kHz in the Americas with 10 kHz spacing. Audio engineers use it for sampling rates: 44.1 kHz comes from the Compact Disc, which Sony used from 1979, and the rate was originally chosen so digital audio could fit on video tape for both PAL and NTSC. Because sampling must exceed twice the highest frequency, 44.1 kHz comfortably covers hearing up to 20 kHz.

1 kilohertz = 1,000 hertz (exactly).

Sources: Wikipedia: Medium wave; Wikipedia: 44,100 Hz; Wikipedia: Kilohertz

Millihertz (mHz)

Metric (SI)Current unit

One thousandth of a hertz: one cycle every 1,000 seconds.

Millihertz describes oscillations so slow that a single cycle takes many seconds. One millihertz is 0.001 hertz, a period of 1,000 seconds, or about 16.7 minutes. At the other end of the scale, one revolution per minute works out to roughly 16.7 mHz, which is how a clock's second hand turns.

Slow phenomena are the natural home of the unit. The planned space-based gravitational-wave detector LISA is designed to operate from 0.1 to 10 mHz, a band that ground detectors cannot reach. The milli prefix is the SI factor of one thousandth, so a millihertz is a thousand times smaller than a hertz and a billion times smaller than a terahertz. Where signals are slower still, such as a daily cycle near 11.57 microhertz, microhertz take over.

1 millihertz = 0.001 hertz (exactly).

Sources: Wikipedia: Hertz; Wikipedia: Orders of magnitude (frequency); Wikipedia: Revolutions per minute

Related conversions

See all frequency units.