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What are bits and bytes?

Written by Max Beckett, Broadband Expert

19 June 2020

Looking for a new mobile data plan or trying to figure out what your broadband speed is? Then you’ll probably have come across bits and bytes - but what are they? Read on to find out.

Bits and bytes

Are bits and bytes the same thing?

No, they’re not, as confusing as that may be. 

There are eight bits in every byte, making bytes the bigger unit.

The way these data units are used also differ.

Bits are used to measure speed.

Bytes are used to measure size.

So, if a 20MB (that’s 20 Megabytes) file is being downloaded at 20MBps (that’s 20 Megabits per second) you’ll need eight times the bits to cover the bytes. That means you won’t get in it one second just because both your bytes and bits are valued at 20 – you’ll get it in eight seconds, because a byte is eight times larger than a bit. 

Of course, in reality, you won’t need to be working out these sorts of mathematical equations. The only thing you really need to keep an eye on is your data allowance to ensure you have enough bytes left to cover your downloads and usage.

What uses bits and bytes?

Everything, essentially. Your digital files or data allowance on your mobile are measured in bytes, and you use data for anything you need mobile broadband for, including:

  • Email

  • Instant messaging

  • Video calls

  • Social media

  • General browsing

  • Online app use

  • Streaming

  • OS updates

Your home PC will also measure its storage in bytes, so you’ll know how much free space you have for programs and files – overloading your PC, or your phone, can cause it to get sluggish.

Your connection speed, such as your home broadband speed, is measured in bits and these figures will help you differentiate between superfast and ultrafast broadband.

What’s the difference between a megabit and a megabyte?

The same rules apply for megabits and bytes – one is for speed, one is for size, the prefix just tells you how many bits or bytes you’re working with:

1024 bytes/bitsKilo
1024 kilobytes/kilobitsMega
1024 megabytes/bitsGiga
1024 gigabytes/bitsTera

Photos and documents will often be measured in KB, while most other media will start hitting MB territory. Large files like programs will be measured in GB and TB is usually reserved for measuring the full capacity of hard drive storage. 

How can I tell bits and bytes apart?

Bits and bytes use the same letters in the abbreviations, which can be confusing, but he clue is in the formatting.

A byte is written with a large B, so, a 1000 byte file is labelled as 1KB. 

A bit is written with a small b, so, 1 bit speed is labelled as 1kb. 

It can be a little tricky, but in the general scheme of things, not knowing the correct formatting for your data labels is hardly going to hold you back. 

How do I calculate gigabit to megabyte and so on?

Like we said, breaking out the GCSE maths isn’t vital to understanding bits and bytes – you’re certain to have a current broadband or phone plan on the go and you’ve done perfectly well without knowing the mathematics behind it all. Still, if you do want to get down to the nitty gritty, remember that a byte is eight times bigger than a bit.

So, if you are looking for a new broadband plan that offers 65Mbps and your file is 130MB, you’ll need 16 minutes. Of course, most files sizes aren’t going to be perfect multiples of your download speeds, so this maths can soon become unwieldy and, for the most part, unnecessary. Plus, as ever, Google will happily tell you the answer. 

How many bits should my broadband connection have?

There’s no set number your broadband should be, but as a general standard, you’ll need at least 9Mb to be on basic ADSL internet. The more bits you have, the faster your broadband. Fibre optic options open up your speeds to be superfast and ultrafast, here’s a quick rundown of the numbers you should be looking for so you don’t get wrongly sold an internet plan:


Most UK households can get by with Superfast speeds, even with streaming and game consoles on the go. Ultrafast will let you add more devices and demand HD quality. Hyperfast is still something of a work in progress, with only some providers like Hyperoptic offering it in very select areas. 

Can my internet get more bits?

You can certainly look to upgrade your broadband plan so you get faster speeds, but keep in mind that some things will affect your performance no matter how much you pay out:

  • Your distance from the telephone exchange

  • The quality of the network cables in your area

  • The presence of fibre optic cables in your area

  • The presence of ultrafast/hyperfast providers in your area

Converting bits and bytes

You can’t directly convert bits to bytes any more than you can convert a kilometre to a litre, as they are used to measure different things. However, if you find that free space on your phone or PC storage is starting to dwindle, you can compress files. You’ll be surprised how much space you can save this way. 

For example, 10 word documents come in at about 325KB, compressed as a ZIP file, you can knock at least 20KB off the total. The other alternative is using a SD card, so long as you have a phone that allows for this. Unfortunately, the iPhone does not.

Do I need to know about bits and bytes?

Not especially. You should definitely familiarise yourself with what they mean. For example, knowing about bytes can help you understand things like phone storage, download capacity or even email attachments. Understanding bytes can also give you better understanding of the broadband plans you’re signing up for. 

It can also help you manage your data allowance better if you know an ultra HD movie comes in at 18GB while the same movie at 1080p (more than enough for mobile viewing) is a mere 2GB. That’s a huge data saving, and really, how much HD detail can you appreciate on a phone screen?

Finding the best deal on bits and bytes

Is it impossible to get a great phone deal or cheap internet without knowing what a bit or a byte is? Certainly not. Especially as Money.co.uk lets you run price comparisons so you can get a clear idea of which deal is best for you in just a few clicks.