You’ve probably heard of a megabyte before, but what about a petabyte? And even if you have heard of a petabyte before, can you tell the difference between a petabyte (PB) vs a megabyte (MB)?
Don’t be dismayed if the answer is no. These two separate units of information found in the world of computing can start to look a little confusing as you rise through their ranks.
Let’s break down the difference between petabyte (PB) vs megabyte (MB) below, making sure to outline exactly what sets these two units of information apart — plus, where you’re most likely to encounter them in the real world.
Petabyte (PB) vs Megabyte (MB): Side-by-Side Comparison
Petabyte | Megabyte | |
---|---|---|
Bytes | 1,125,899,906,842,624 | 1,048,576 bytes |
Gigabytes | 1,048,576 gigabytes | 0.0009765625 gigabytes |
Symbols | PB, PiB | MB, MiB |
Follows | Terabyte | Kilobyte |
Followed By | Exabyte | Gigabyte |
Petabyte (PB) vs Megabyte (MB): What’s the Difference?
Now that we’ve laid out some of the basic specifications that define the petabyte (PB) vs megabyte (MB), let’s spend some time talking about exactly what a petabyte is compared to a megabyte.
After all, it’s one thing to know how many bytes or gigabytes go into a unit of information, but it’s an entirely different thing to know what that means in the grand scheme of things. Let’s begin with the petabyte, then move on to the megabyte.
Petabyte Explained
When computers first emerged on the market, there was no real need for much additional storage beyond the unit of information known as the gigabyte. This seems like a paltry sum by today’s standards, however.
In the 2020s, you’d be completely hopeless trying to do any sort of contemporary computing equipped with just one gigabyte. These days, the tech titans of the industry have blown past the gigabyte and even the terabyte. Nowadays, the petabyte — that’s 1,000,000 gigabytes — is what the real heavy hitters rely on.

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Considering how much memory is currently offered on many of the latest smartphones, tablets, gaming consoles, and computers (both desktop and laptop), it’s only a matter of time before consumers evolve onto the petabyte, as well.
Granted, this won’t happen next year (and maybe not even next century), but it’s nevertheless the next unit of information after the current consumer standard known as the terabyte (or TB). It’s three steps up from the much smaller megabyte and is commonly noted as 1000 units to the fourth power.
When working with binary notation, this number (distinctly labeled the “pebibyte” instead of the “petabyte” to better distinguish between the two values) changes to 1024 to the fifth power.
For reference, a megabyte in binary notation — which is labeled as “mebibyte,” a term we’ll elaborate more on below — changes to 1024 to the second power. Another way of looking at the petabyte in binary notation is to write it out in full: that’s 1,125,899,906,842,624 bytes per single pebibyte. (That’s 15 zeroes, to be clear.)
Megabyte Explained
While the petabyte is a long way off from the kilobyte — one of the former is equivalent to a quadrillion of the latter — the megabyte is just a single step up from the kilobyte. It goes without saying that these two units of information pale in comparison to the size of a gigabyte.
However, a megabyte remains larger than a kilobyte by comparison. If you were to arrange them from smallest to largest, it would go kilobyte, then megabyte, then gigabyte. Compared to a petabyte, a megabyte is worth just one thousand kilobytes. (That’s one million bytes in all, or slightly more in binary notation.)

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Similarly to the petabyte, these exact numbers change when you switch over to binary notation. (Binary notation is the preferred way to convey this unit of information in the field of computer science, where binary digits are much preferred over the well-rounded numbers of decimal notation which exclusively uses units of 10.)
In binary notation, a “megabyte” is, instead, labeled a “mebibyte.” Its abbreviation changes, as well, switching from “MB” to “MiB.” Likewise, petabyte (PB) changes to pebibyte (PiB). Ultimately, a megabyte is equivalent to 1,000,000 bytes, while a mebibyte is 1,048,576 bytes.
This “mebibyte” terminology is not the same as the “megabit.” This is something else entirely different. Instead of dealing with storage and varying amounts of bytes, the megabit deals with speed. More specifically, the speed at which digital information travels.
This particular variation is abbreviated as “Mb.” There’s also a petabit, which is abbreviated as “Pb.” A megabit is a million bits of data, whereas a petabit is one quadrillion bits of data. (You might’ve been able to assume this, knowing the conversions for both megabytes and mebibytes.)
Petabyte: Real-World Examples
Now, where in the world might you encounter a petabyte in the wild? You surely won’t see this digital unit of information as a possible storage option for your smartphone or your laptop today, but that doesn’t mean that the unit isn’t used on a daily basis in our tech world. Here are two popular instances.
Social Media Data

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On average, most of the biggest social media sites of our current day and age see several petabytes of data every 24 hours. This racks up fast, resulting in many dealing with exabytes of data annually.
From Facebook to Instagram to Snapchat, these four or five petabytes a day will only continue to increase as more users log on and share higher-quality images, videos, links, and beyond.
Twitter sees plenty of data, as well, but its output is a little smaller — around a petabyte a day. Twitter is far more text-based than Facebook, Instagram, or Snapchat, hence the smaller data.
Google Maps
If you’ve ever goofed around on Google Maps — or used it seriously, of course — you know that Google’s digital representation of the world’s roads is truly a behemoth. From turn-by-turn navigation to its iconic street view option, Google Maps is a massive undertaking done incredibly well.
To store all this Maps information, Google needs about 20 petabytes or more. This number continues to grow with each new update to the service — not to mention with each new trip around the world, as they collect updated photos of our planet’s roads.
Megabyte: Real-World Examples
Now for the megabyte. We have a much clearer idea of how the petabyte plays a part in our daily lives, so let’s do the same for the megabyte. And, unlike the petabyte, you’ve undoubtedly encountered far more instances of the megabyte in your typical day-to-day than the petabyte. Here are two of the unit of information’s most traditional uses.
Larger File Sizes
Every text message you send can appropriately be measured in kilobytes. A paragraph of text on a document also measures out according to this smaller unit. Alas, not every document or text measures out to just a few lines.
Most of the emails, text documents, and picture messages we send back and forth to one another can be measured more accurately in megabytes. A PDF typically weighs around two megabytes.
An audio message, by comparison, will weigh in around a single megabyte. A novel-length word document will come in at around three megabytes.
Mobile Data
Every text you send, every video you stream, every FaceTime call you make, every feed you refresh… it all comes at the cost of megabytes of data. No, not megabits — we already discussed the difference there. We’re talking megabytes.
Streaming music for an hour will use around sixty to a hundred megabytes of mobile data in all. An hour of Netflix will eat up much more — closer to 800 megabytes, perhaps even a full gigabyte if the quality is high. The average smartphone owner uses around four hundred to five hundred megabytes of mobile data each day.
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