Computing, radio transmission, audio engineering – these diverse fields all rely on the humble hertz for measuring frequency. In this guide, we‘ll provide a full comparison of megahertz vs kilohertz. You‘ll learn the history behind these important units, their relationship to each other, common uses, and guidelines for choosing which one to use. Let‘s get started!
A Brief History of the Hertz
First, a quick physics refresher. The hertz (Hz) is the basic unit of frequency defined as one cycle per second. For example, a hummingbird flaps its wings around 50 times per second, or 50 Hz. The concept is credited to Heinrich Hertz, the pioneering German physicist who confirmed the existence of radio waves in the late 1880s.
Hertz showed that electricity could be transmitted through open air, proving James Clerk Maxwell‘s theory of electromagnetism. This groundbreaking work laid the foundation for radio technology and our understanding of electromagnetic radiation. In honor of his contributions, the unit of frequency was named after Hertz when it was adopted by the International Electrotechnical Commission (IEC) in 1930.
Heinrich Hertz conducted pioneering experiments that proved the existence of radio waves. [Source: Springer]
So next time you turn on your radio or connect to WiFi, thank Heinrich Hertz! His discoveries launched the era of wireless communication.
What Is a Hertz?
As mentioned above, one hertz equals one cycle per second. A cycle is the complete sequence of values for something that oscillates or repeats periodically. Examples include:
- A guitar string vibrating 440 times per second = 440 Hz
- AC power alternating 60 times per second = 60 Hz
- A laser pulse flashing 1000 times per second = 1000 Hz
Anything that oscillates has a measurable frequency in hertz. The context determines what exactly constitutes one cycle, but the underlying meaning is the same – events per second.
Understanding hertz helps conceptualize the larger frequency units of kilohertz and megahertz. Now let‘s examine those in more detail.
Megahertz vs Kilohertz: Side-by-Side Comparison
|1 x 10^6 Hz
|1 x 10^3 Hz
|Hectohertz (100 Hz)
|Gigahertz (1 billion Hz)
|Early computer CPU speeds, electronics
|Radio technology, telegraph
|1 MHz, 10 MHz, 100 MHz
|1 kHz, 10 kHz, 100 kHz
|Commonly used to measure
|Wireless transmitters, computer processors, data buses
|Audio, wireless transmitters, alternating currents
Megahertz vs Kilohertz: What‘s the Difference?
Looking at the table comparisons, the difference between megahertz and kilohertz becomes clear:
- 1 MHz = 1,000,000 Hz
- 1 kHz = 1,000 Hz
So megahertz measures millions of hertz, while kilohertz only measures thousands of hertz. It‘s purely a scale difference – but an important one!
For example, let‘s say a computer processor runs at 2,400,000,000 Hz. That‘s a lot of zeroes! Using megahertz simplifies it down to a nice even 2.4 GHz.
Or on the audio side, a tweeter speaker playing a 22,050 Hz tone would be stated as 22.05 kHz instead.
Choosing the right scale unit removes excessive zeroes and keeps frequency measurements tidy. Kilohertz works for the thousands range, megahertz for the millions range, and gigahertz for billions.
Now let‘s examine some of the common uses for each unit.
Megahertz vs Kilohertz: Common Uses
Kilohertz frequencies dominate many electrical and audio engineering applications. For example:
Audio frequencies – The human hearing range falls between 20 Hz to 20 kHz. Music and voices contain audible tones up to the lower kilohertz range. Audio equipment focuses mainly on kilohertz or smaller units.
AC power – Alternating currents like the electrical mains oscillate at 60 Hz in North America and 50 Hz in much of the world. This puts them in the zero to hundred hertz range.
AM radio – AM broadcasting transmits in bands from 535 kHz to 1705 kHz. The kilohertz scale matches the technology.
Wireless transmission – Short range devices like WiFi, Bluetooth, and garage door openers transmit below the megahertz level, using kilohertz frequencies.
Computer components – Older peripherals like caches and buses operated in the kilohertz range before advancing to megahertz speeds.
Now let‘s look at some common megahertz uses:
FM radio – FM radio stations broadcast between 87.5 MHz to 108 MHz, right in the megahertz sweet spot. The higher frequencies enable higher fidelity than AM.
TV transmission – Analog TV signals were allocated channels between 55.25 MHz to 885.25 MHz before switching to digital. The 700 MHz band is still used for DTV.
Cell service – Mobile networks like 4G LTE rely on a wide range of megahertz frequencies from 700 MHz up through 2500 MHz. 5G uses frequencies in the 3000 MHz to 5000 MHz ranges and above.
WiFi – While older WiFi transmitted below 1 MHz, modern 802.11 standards employ higher frequencies up to 5 GHz for faster transmission rates.
Computers – Personal computer CPUs surpassed 1 MHz in the 70s and now commonly operate in the gigahertz range. Buses transfer data at speeds measured in megahertz.
Physics research – Particle accelerators and advanced physics experiments may use electromagnetic radiation up to the terahertz range and beyond.
As you can see, kilohertz and megahertz both have importance across scientific and engineering fields. But what determines which one you should use?
When to Use Megahertz vs Kilohertz
Choosing the appropriate unit comes down to matching the scale to the frequencies involved:
Audio applications rarely need to measure above 20 kHz, so kilohertz is suitable here. Stating a 15,00 Hz tone as 15 MHz would be incorrect.
On the other hand, the megahertz range fits FM radio stations transmitting at 100 MHz. Expressing this as 100,000 kHz would introduce excessive zeroes.
For computers, kilohertz works for slower components, while megahertz matches the speeds of CPUs and buses. Gigahertz is used as speeds increase.
Wireless networks transitioned from kilohertz to megahertz as data rates increased from early WiFi to 5G.
Physics experiments may reach into gigahertz, terahertz, or beyond as needed to measure their extreme frequencies.
The application and specific frequencies involved dictate which units make sense. Use kilohertz for the audio and low-frequency electronics work, while reserving megahertz for higher-speed computing and radio applications.
Gigahertz, terahertz, and larger units build from there as frequencies climb higher. Matching the scale provides clean and sensible measurements.
Megahertz vs Kilohertz: Which One Is Better?
Given their different uses and scales, neither megahertz nor kilohertz are inherently "better" than the other. Kilohertz has advantages for audio and low-frequency electronics:
- Keeps numbers tidy in the human hearing range
- Avoids excessive zeroes with lower frequencies
- Aligns with AM radio, AC power, and devices like Bluetooth
Meanwhile, megahertz has benefits for higher-frequency applications:
- Simplifies the millions and billions range
- Works well for FM radio, TV, cell networks
- Matches CPU speeds, data buses, and physics experiments
Choosing the right tool for the job provides optimal readability. An audio engineer tuning a 15,000 Hz filter to 15 kHz makes more sense than saying 15 MHz. Similarly, stating a 1.2 GHz CPU speed as 1,200,000 kHz is needlessly complex.
Use the unit that best fits the frequencies involved – kilohertz for thousands of hertz, or megahertz for millions and above. Both have importance in technical fields, and neither is universally "better." Choose wisely based on the context!
Hertz Help You Master Frequency
We covered a lot of ground explaining these fundamental frequency units. The key takeaways are:
Hertz (Hz) measures cycles per second, a basic building block across science and engineering.
Kilohertz (kHz) measures thousands of hertz, used for audio, AC power, AM radio and lower frequency electronics.
Megahertz (MHz) measures millions of hertz, suitable for FM radio, wireless networks, computer speeds and high frequency physics research.
Neither is inherently better – choose the unit that fits the frequency range needed.
Understanding the relationship between hertz, kilohertz, and megahertz unlocks a deeper mastery of frequency for any technical field. Thanks for learning with us today!