MHz vs Hz: What's the Difference?
MHz and Hz are not two different quantities. They are the same frequency written with different metric prefixes: hertz is the SI base unit, and megahertz is that unit multiplied by one million. Choosing between them is a question of readability and of the convention used by the datasheet, standard or instrument you are reading.
2 min readPublished August 25, 2026Updated September 10, 2026
One quantity, two scales
Frequency counts how often something repeats each second. Saying 88 MHz and 88,000,000 Hz describes the same radio station, not two different measurements. Whenever you compare "MHz vs Hz", you are comparing how a number is written, not what it means.
Hertz: the SI base unit
The hertz is named after Heinrich Hertz and defined in the SI system as one cycle per second. Anything that repeats once per second has a frequency of 1 Hz, which makes the unit the common language of audio, electricity and mechanics.
- Mains electricity: 50 Hz in most countries, 60 Hz in North America.
- Human hearing: roughly 20 Hz to 20,000 Hz.
- A resting heartbeat: about 1 Hz.
- Visible light: 400 to 790 terahertz — the same unit, scaled far beyond megahertz.
Megahertz: one million hertz
Megahertz applies the metric prefix mega- (10⁶) to the hertz. It exists for the same reason kilo- exists for metres: 88,000,000 Hz is easy to misread and hard to say aloud, while 88 MHz is neither. Broadcast engineering and consumer hardware settled on MHz long before gigahertz became commonplace.
The frequency prefix ladder
Each step multiplies by 1,000, so moving between neighbouring units shifts the decimal point three places at a time.
| Unit | Symbol | Value in hertz | Typical use |
|---|---|---|---|
| hertz | Hz | 1 | Audio, mains electricity, base SI unit |
| kilohertz | kHz | 1,000 | AM radio, audio bandwidth |
| megahertz | MHz | 1,000,000 | FM radio, processor clocks, Wi-Fi |
| gigahertz | GHz | 1,000,000,000 | Modern processors, radar, Wi-Fi |
MHz vs Hz at a glance
| Hz | MHz | |
|---|---|---|
| Value | 1 cycle per second | 1,000,000 cycles per second |
| Scale | SI base unit | 10⁶ × the base unit |
| Typical range | 1 Hz – 20,000 Hz | 0.1 MHz – 5,000 MHz |
| Written example | 2,400,000,000 Hz | 2,400 MHz |
| Common homes | Audio equipment, mains, sensors | Radio, Wi-Fi, CPU clock speeds |
Which unit should you use?
- Follow the source. A datasheet, standard or test instrument usually states the unit it expects, and matching it avoids transcription errors.
- Keep numbers readable: pick the prefix that leaves one to three digits in front of the decimal point.
- Use hertz when a formula requires SI base units, then convert back only for presentation.
- Never mix prefixes inside one calculation. Convert every value to hertz first, calculate, and convert the result at the end.
Quick answer
Frequently asked questions
Is 1,000 Hz the same as 1 MHz?
No. 1,000 Hz is one kilohertz. 1 MHz is 1,000,000 Hz — a thousand times larger.
Can I write megahertz as hertz?
Yes, by adding six zeros: 2.4 MHz is 2,400,000 Hz. Both forms are correct, so pick the one your reader or your software expects.
Does MHz measure speed?
No. MHz measures frequency, not data rate. Transfer speeds use bits per second, which is a different quantity even though both use decimal prefixes.