Bits ‘n’ Bytes, What You Need to Know

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OK, so some would say you really don't need to know what I’m going to explain here. I have a different view. For the small amount of time it will take you to learn some basic knowledge I think you will find it very worthwhile as it will always be relevant.

So, Bits and Bytes, What the Heck Are They?

In our everyday number system – decimal - we use ones, tens, hundreds, thousands - and we probably all remember at school we had a units column, tens column, hundreds column for our junior learning.

The little numbers 2,1,0 are ‘to the power of’ and we probably remember thinking of the 2 as the square of a number. So 102 is ten squared which equals 100.

three x hundred +
five x ten +
seven x one
= Three hundred and fifty-seven – 357.

Hope you’re still with me already 😉

This is the tens based number system.

Computers use the binary number system based on 2. Why 2? On and off. Electronic circuits (think of a battery wired to a light bulb via a switch) – either the switch is open or closed and the light bulb will correspondingly be off or on. 0 or 1. That’s how it came about. Obviously things have moved on a bit since then. Anyway, using the same idea of columns we can write:

And here we can only enter ones and zeros – 1s and 0s. So looking above 10110101 is an 8 digit binary number. Which in decimal is:

1 x 128 +
0 x 64 +
1 x 32 +
1 x 16 +
0 x 8 +
1 x 4 +
0 x 2 +
1 x 1
= 181

Easy, huh?

So a 1 or 0 is called a bit. And we call 8 bits a byte. So always remember that to convert bytes to bits, multiply by 8. So bits to bytes divide by 8. And pay attention to what you hear as when speaking they can easily be confused. A kilobyte can sound like a kilobit in an unclear phone call.


Moving on, we have the American Standard Code for Information Interchange, ASCII for short. This defines how we represent characters – letters, digits, symbols. The following is just an extract of the whole set so you can get the idea.

So to spell Bad you’d need:


Which is 3 bytes 😊 or a total of 24 bits.

Now, if we think about communicating that we would need to send it down a wire. You could think in terms a bit like Morse code where someone opens and closes a switch on a wire that goes to a light bulb somewhere, and somewhere could be a long distance away. So by observing the light bulb you could write down the series of ons and offs then look them up in the table above to work out what was being sent.

That is a very crude explanation but it is also basically how it works. Very simple to understand really. However, modern reality is much more complex – it is not just the 1s and 0s of your message that get sent, there is a whole bunch of other data that gets added to the message. But I am not going into any of that here really. The data that gets added to your basic message includes data about sender and receiver, error checking and correction. And of course, the internet isn’t a wire with a switch connected to some lightbulb somewhere. The internet is a vast web of interconnected computers, connected by fibre optic cable networks, copper cable networks, Wi-Fi, routers, servers, and a ton of other technical wizardry that allows young Peter in New York to video chat with his Mum who is working in London via the internet.

All I want you to know is what a bit is and what a byte is. And from there we can deduce that a kilobyte is roughly a thousand bytes (actually it is 1,024). So:

1kbyte = 1,024 bytes = 1,024 x 8 bits = 8,192 bits
1Mbyte = 1,024 kBytes = 1,024 x 1,024 x 8 bits = 8,388,608 bits

Get the idea? Great!

  • 👍 Note that the official numbering system uses upper case B and lower case b distinctly: kB is kilobyte, kb is kilobit which as we have learned from the above are a factor of 8 different. I point this out because it is a subtle point and as such I see many references around the internet that are incorrect. Order a 16 kb memory card thinking you'll get a 16 kB memory card and you'll start to appreciate why you might be disappointed with what gets delivered 🙂

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