Convert Frequency from Rotation Per Minute to Hertz (rpm to Hz)
Multiple conversions

rotation per minute to hertz Conversion Formula

To convert from rotation per minute (rpm) to hertz (Hz), use the following formula:

Example

Let's convert 5 rotation per minute (rpm) to hertz (Hz).

Using the formula:

Therefore, 5 rotation per minute (rpm) is equal to $0.083333333333333333335$ hertz (Hz).

What is RPM? A Simple Guide to Rotations Per Minute

Simply put, rotations per minute (RPM) measures the speed at which something is spinning.

It counts the number of full turns an object completes in one minute. From car engines to computer hard drives, RPM is a key indicator of performance and speed.

The History of RPM: From Steam Engines to Horsepower

The concept of RPM (rotations per minute) gained popularity during the Industrial Revolution, thanks in large part to Scottish engineer James Watt.

While developing his steam engine, Watt needed a way to compare its power output to that of a horse. To do this, he determined how many times a horse could turn a mill wheel in one minute.

He utilized this rotational measurement to help establish the definition of horsepower. As a result, RPM became a crucial metric for quantifying the performance and work capacity of mechanical engines—a practice that continues to this day.

Where You See RPM in Action Every Day

You encounter RPM every day in common technology.

In your car, the tachometer displays the engine's speed in rotations per minute, indicating how fast the crankshaft is spinning. A higher RPM generally means more power is being produced.

Computer hard disk drives (HDDs) also use RPM to measure their performance; a 7200 RPM drive can read and write data faster than a 5400 RPM drive.

RPM ratings, which denote motor speed and efficiency, are also found on household appliances such as blenders, washing machines, and fans.

How to Convert RPM to Other Units

Although RPM is a common unit, physics and engineering often use hertz (Hz) for frequency and radians per second (rad/s) for angular velocity.

The conversion is straightforward:

• To Hertz (Hz): Because a minute has 60 seconds, you divide the RPM value by 60.

  • Frequency (Hz) = RPM / 60

• To Radians per Second (rad/s): One complete rotation is equivalent to 2π radians. To convert RPM to radians per second, multiply the RPM value by 2π, then divide by 60.

  • Angular Velocity (ω in rad/s) = (RPM × 2π) / 60

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 the International System of Units (SI)?

rotation per minute to hertz Conversion Table

Here are some quick reference conversions from rotation per minute (rpm) to hertz (Hz):