Convert Frequency from Hertz to Millihertz (Hz to mHz)

hertz to millihertz Conversion Formula

To convert from hertz (Hz) to millihertz (mHz), use the following formula:

Example

Let's convert 5 hertz (Hz) to millihertz (mHz).

Using the formula:

Therefore, 5 hertz (Hz) is equal to $5000$ millihertz (mHz).

What Is a Hertz (Hz)?

Hertz (Hz) is the standard unit of frequency, measuring the number of cycles per second.

You encounter it everywhere in modern technology, from the sound you hear and the screen you're looking at to the speed of your computer's processor (CPU). The plural form is simply hertz.

Who Was Heinrich Hertz?

The unit is named in honor of the German physicist Heinrich Rudolf Hertz.

In the late 1880s, he was the first person to provide conclusive proof of the existence of electromagnetic waves. His groundbreaking experiments laid the groundwork for the development of radio, television, and all forms of wireless communication.

What Is Hertz Used For in Everyday Technology?

Hertz is a fundamental measurement you encounter in everyday technology, often without realizing it. Here are two of the most common examples:

Sound Waves and Pitch

A sound's pitch is determined by its frequency (measured in hertz): higher frequencies produce higher pitches.

For example, the A above middle C on a piano is standardized at 440 Hz.

Screen Refresh Rates (60 Hz vs. 120 Hz)

The refresh rate of your computer monitor, TV, or smartphone screen is measured in hertz.

This number indicates how frequently the display updates the image per second—a higher value results in smoother motion, which is especially noticeable in videos and gaming.

• 60 Hz: Updates the image 60 times per second. This is the standard for most displays.
• 120 Hz: Updates 120 times per second for much smoother on-screen movement, making it great for gaming.
• 240 Hz: Updates 240 times per second, offering exceptionally fluid motion for professional and competitive gamers.

What Does Gigahertz (GHz) Mean for Computers?

When discussing computer processors, you often hear the term gigahertz (GHz). One gigahertz is equal to one billion hertz (1 GHz = 10⁹ Hz).

This value represents the processor's CPU clock speed—the number of processing cycles it can execute per second.

Before gigahertz became the standard, speeds were often measured in megahertz (MHz), where 1 GHz equals 1,000 MHz. While not the sole indicator of performance, a higher clock speed generally means a processor can perform calculations and execute instructions more quickly.

What is a millihertz (mHz)?

Ever wondered how scientists measure incredibly slow, barely-there movements, like the subtle shifting of continents or the rhythm of a distant star?

They often use a special unit of frequency called the millihertz (mHz).

A millihertz is a unit of frequency equal to one-thousandth of a hertz (0.001 Hz). It's designed to measure things that happen very, very slowly.

What is Millihertz Used For?

While a standard hertz (Hz) measures cycles per second (think sound waves or computer speeds), a millihertz measures events that occur very slowly, taking a very long time to complete a single cycle.

To put it in perspective, something oscillating at one mHz takes 1,000 seconds—or nearly 17 minutes—to complete just one cycle!

This makes the unit perfect for tracking extremely slow phenomena.

Key applications include:

• Seismology: Geologists use mHz to study the slow-moving seismic waves generated by "slow earthquakes," which can last for hours or even days.
• Astrophysics: The unit is used to describe the gentle pulsations of certain types of stars, helping astronomers understand what's happening deep inside them.

How Do Millihertz Relate to Time?

Frequency and time are two sides of the same coin.

In physics, the time it takes for one complete cycle is called the period (T), while frequency (f) refers to the number of cycles that occur per second. They are inversely related: as one increases, the other decreases.

The relationship is expressed as T = 1/f.

To find the period in seconds from a frequency in mHz, you first convert mHz to Hz (1 mHz = 0.001 Hz) and then find its reciprocal.

Formula:

• Period (in seconds) = 1 / (frequency in mHz × 0.001)

Example:

• An oscillation of 2 mHz has a period of 1 / (2 × 0.001) = 1 / 0.002 = 500 seconds.

Why is Millihertz Important for Astronomy?

The mHz range is crucial for one of the most exciting fields in modern astronomy: the search for gravitational waves.

Space-based observatories, such as the Laser Interferometer Space Antenna (LISA), are specifically designed to detect low-frequency gravitational waves in the millihertz band.

These ripples in spacetime are believed to be caused by some of the most massive and dramatic events in the universe, such as:

• The merging of supermassive black holes at the centers of galaxies.
• The orbital dance of compact binary star systems.

Detecting signals in the millihertz band offers scientists a unique opportunity to explore cosmic events, allowing them to observe the universe in a completely new way.

What is the International System of Units (SI)?

hertz to millihertz Conversion Table

Here are some quick reference conversions from hertz (Hz) to millihertz (mHz):