Megabytes, Megabits, Gbps & TB: What you need to know

Gigabytes. Megabits. TBs. Kbps. Whew! What a mega headache. There’s more jargon associated with computing, networking, and the internet than you can shake a stick at. And you’ll likely bring out the hecklers if you jump on a Reddit forum and type the wrong “b” as you complain about your internet speed. Sigh.

But here’s the skinny: none of these terms have anything to do with biting into a cookie. Instead, they describe a digital amount. We’ll give you the skinny, then dive deeper with some technical explanations.

Jump to: KB, MB, GB, and TB | Speeds vs. storage | Using bits and bytes | Why the difference matters | Why the difference doesn’t matter | Our verdict

Jump to:

• KB, MB, GB, and TB
• Speeds vs. storage
• Using bits and bytes
• Why the difference matters
• Why the difference doesn’t matter
• Our verdict

What’s the difference between KB, MB, GB, and TB?

KB (kilobytes), MB (megabytes), GB (gigabytes), and TB (terabytes) represent different sizes of file storage, with KB being the smallest measurement and TB being the largest. Check out the chart below for specifics and real-world examples.

How many megabits per second (Mbps) does your internet plan deliver?

To find out, run our speed test from a wired connection and compare the results to your plan’s advertised speed. If you’re on Wi-Fi, move next to the router (if you can) to get the best results from our test.

To find out, install our mobile app, run our speed test next to the router or gateway to get the best results, and then check your numbers against your plan’s advertised speed. For the most accurate speed readings, run the test from a wired connection instead.

Read on to learn about how internet speeds relate to Mbps. Then, get the full explanation of bits vs. bytes … so there’s no chance of catching shade on your next Reddit expedition.

Megabits vs. Megabytes: the quick comparison

The term “megabits” is almost always used to show how much data you can transfer across a network in a second, abbreviated as Mbps. For example, an internet connection may have a bandwidth (or speed) of up to 940Mbps. The term “megabytes” is almost always used to show how much data a storage device can transfer in a second, abbreviated as MBps (or MB/s).

In short, Mbps means speed and MB means storage. It follows, then, that GB means file size and Gbps means speed, and the same is true of KB vs. Kbps and GB vs. Gbps.

The capitalization of that “b” does make a difference.

Do you need gigabit internet?

Gigabit internet is shorthand for internet speeds of 1Gbps, which is equal to about 1,000Mbps. All fiber internet providers we review offer speeds of at least a gigabit, and many cable internet providers now offer plans in that range as well.

Those speeds are impressive, but most households don’t need gigabit speeds. An internet plan with 500Mbps speeds is plenty fast for even the biggest, most binge-happy homes.

Bits vs. bytes: What is the difference?

We promised to get into the technical stuff, and that time has come.

First, it’s true the digital universe is made of nothing but ones and zeroes. In fact, the term bit is short for binary digit, the smallest unit of data. The value is either a “1” or a “0,” although the two values can signify “on” and “off” states or something similar.

So, what is a byte? It’s not what you do when you grab a piece of chicken—that’s a wholly different word. A byte is a group of eight bits, but we also use the term to describe the smallest unit of storage—we’ll explain more about that later.

Keep in mind that any measurement written in bytes is eight times larger than the corresponding unit measured in bits. In other words:

1 megabyte (1MB) = 8 megabits (8Mb)

1 gigabyte (1GB) = 8 gigabits (8Gb)

With us so far?

What are bits and bytes used for?

So, let’s do a quick recap:

• Bit – a single unit of data represented as a one or a zero.
• Byte – a combination of eight bits, like 11001100.

Simple enough, right? Now, let’s look at how we use the two terms.

Bit

Uses: networking and computing

We typically use bits to define the amount of data you can transfer in one second. Why? Because measuring data in motion (downloading and streaming) is trickier than measuring data at rest (files, programs, etc.).

For instance, everything you download—websites, pictures, emails, software, cat videos, and so on—divides into packets and transmits in several different directions, often arriving on your device out of order (and then reorganized). This erratic flow of data isn’t always easy to divide into bytes, so we use bits instead.

So, what does Mbps mean?

Bits per second (bps) is the number of bits moving between two points in a single second. Data transfer rates, upload speeds, download speeds, and bandwidth are almost always measured this way.

So, we obviously don’t want to say or write that our internet connection is 500,000,000 bits per second—500Mbps per second is far shorter.

When we apply this measurement to an internet connection, the most you can download at any given second from a 500Mbps plan is 500 megabits. Plus, we generally think of this number as our top speed, but it’s really the full bandwidth set by your internet provider.

Clear as mud? Read this quick primer on speed vs bandwidth from our expert archives.

Byte

Uses: storage and software

A byte is the smallest storage unit. Hard drives, SSDs, USB sticks, and system memory have almost always listed their maximum capacity, read and write speeds, and transfer speeds in bytes.

Software size is also measured in bytes. One standard character requires a single byte of storage, so storing the word “hello” needs five bytes, one for each letter. This is why all forms of device storage—from RAM to hard drives—are generally measured in bytes.

So, what does MBps mean?

Generally, megabits per second describe the data transfer rate between an internal component and its parent device. For example, a WD Black SSD may have a set storage capacity, but the specifications also list a transfer rate of up to 7,300MB per second. If we wrote that in megabits, the number would be a longer 58,400Mbps, so manufacturers list the shorter number.

You can technically measure speed in bytes per second simply by taking the speed in bits per second and dividing by eight. For example, a 1,000Mbps internet speed converts to 125MB/s. But network speed is almost never measured in bytes, so if you see a speed listed for an internet connection, it’s safe to say that it’s using bits per second.

Megabits vs. megabytes: Why it matters

These subtle differences in units make it easy to flub your math when dealing with your internet speed. If you happen to get them mixed up, your calculations will be off. Way off.

For example, let’s say you want to download a 500MB file, and you have a 100Mbps internet connection. If you don’t notice the capital B in the file size, you might estimate that this download would take five seconds. However, the units don’t match up. The file size is measured in megabytes, while the connection speed is measured in megabits. Since the file size is eight times larger than you originally estimated, it actually takes eight times as long to download—40 seconds.

Now, waiting 35 seconds longer than you expected isn’t too bad, but waiting an extra 35 minutes on a download that was supposed to take only five is more of an inconvenience. This can also be frustrating if you realize you’re paying for an internet connection that gives you a lot less speed than you thought.

Megabits vs. megabytes: Why it doesn’t matter

If you’re having trouble keeping track of all these numbers, relax. Take a deep breath, and get yourself a snack. While it’s important to know the difference between bits and bytes (and to know that there is a difference), you don’t have to worry about making an expensive blunder.

Bits and bytes are used in different contexts

Generally speaking, network speed always uses bits, and storage capacity and speed always use bytes. More specifically, all internet providers list plans in megabits and gigabits, like 500Mbps and 5Gbps. All storage drive manufacturers list capacities and transfer speeds in megabytes, like 500MB and 7,500MB/s, respectively.

You never have to worry about converting between units. Even if a provider wanted to be sneaky and measure its speed in MBps instead of the standard Mbps, it would only make their connection look eight times slower than competing plans. What looks faster to you? 1,000Mbps or 125MBps?

You’ll never need to calculate exact download times

When you download a large file, modern browsers calculate the download time for you automatically. But even these exact calculations are rarely spot-on because there are so many other factors that impact how long it takes your data packets to download.

The important thing to know about your internet speed is not what volume of data it could download in an ideal situation, but whether or not it’s fast enough to do what you want it to do.

Our verdict: Knowing the difference can be useful

Megabits are used to measure wired and wireless speeds (Mbps). Megabytes are used to measure storage capacity and how fast storage devices transfer data (MB/s). Bytes are made up of eight bits, so to convert a value in bits to bytes (or Mbps to MBps, Gbps to GBps, etc.), simply divide the value by eight:

• 1,000 megabits per second ÷ 8 = 125 megabytes per second
• 250 megabytes per second x 8 = 2,000 megabits per second

Knowing the difference between bits and bytes is useful for navigating discussions about internet technology and other digital devices. It can also help you ask more useful questions when dealing with tech support or customer service.

Fortunately, in this case, knowing is significantly more than half the battle. Situations where you have to actually do the math rarely pop up outside of a computer science quiz. But now that you can do the math if you need to, get ready to amaze your friends next time this category pops up on Jeopardy!

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