Gigahertz to Millihertz (GHz to mHz)

1 gigahertz equals 1,000,000,000,000 millihertz exactly.

1 gigahertz = 1,000,000,000,000 millihertz

How to convert gigahertz to millihertz

To convert gigahertz to millihertz, multiply the number of gigahertz by 1,000,000,000,000. This factor is exact. To go the other way, multiply millihertz by 1×10⁻¹².

millihertz = gigahertz × 1,000,000,000,000

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

About these units

Gigahertz (GHz)

Metric (SI)Current unit

One billion hertz. Modern processor clocks and Wi-Fi run at gigahertz frequencies.

On 6 March 2000, AMD demonstrated a processor passing the 1 GHz mark, a few days before Intel shipped 1 GHz systems, according to Wikipedia. After that, clock rates rose more slowly: Intel's 3 GHz Pentium 4 arrived in 2002, and later performance came more from design changes than raw speed, since higher clock rates produce more heat. The highest boost clock on a production processor is listed as 6.2 GHz for the Intel i9-14900KS in 2024.

A gigahertz is a billion hertz, the range known as microwaves. The most familiar example may be the kitchen: consumer microwave ovens typically run at 2.45 GHz, a band that is available for industrial, scientific and medical use worldwide. Percy Spencer of Raytheon discovered the heating effect in 1945 when a radar set melted a candy bar in his pocket, and Raytheon sold the first commercial oven, the Radarange, in 1947.

1 gigahertz = 1,000,000,000 hertz (exactly).

Sources: Wikipedia: Clock rate; Wikipedia: Microwave oven; Wikipedia: Gigahertz

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.