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Bits and bytes explained

Can't tell your bits from your bytes? Read on to learn the lingo.

Connection speeds and data sizes are measured differently, but people tend refer to them with the same names. People often say 'megs' and forget that the word 'meg' refers to two very different values. Do they mean megabits or megabytes? Aren't they the same?

Actually no, there's a big difference between a bit and a byte. A byte is much bigger — eight times bigger, in fact, with eight bits in every byte. By extension, there are eight megabits in every megabyte, and one gigabyte is eight times bigger than one gigabit.

You're losing me with all this maths. How does this relate to me?

Let's say you find a file online that is 24 megabytes (MB) in size, and you want to download it using your 24 megabit per second (Mbps) broadband connection. This won't take one second, it will take eight times one second because a MB is eight times bigger than a Mb. So in theory (and with a perfect speed), it will take eight seconds to download.

bytes and bits explained

How do I know if it's a bit or a byte?

From how it is spelt. A byte is an uppercase 'B' and a bit is a lowercase 'b'. If it says MB, all capitals, then it is a megabyte. If it says Mb, then it is a megabit. There is one exception to this, of course, and it is the symbol for kilobit, which is 'kb', all lowercase.

What other measurements should I know?

For practical purposes, you will only need to know a little bit (no pun intended). Kilos, megas, gigas and teras should see you through for the next few years or so.

KB, MB, GB - A kilobyte (KB) is 1,024 bytes. A megabyte (MB) is 1,024 kilobytes. A gigabyte (GB) is 1,024 megabytes. A terabyte (TB) is 1,024 gigabytes.

kb, Mb, Gb - A kilobit (kb) is 1,024 bits. A megabit (Mb) is 1,024 kilobits. A gigabit (Gb) is 1,024 megabits. A terabit (Tb) is 1,024 gigabits.

Don't forget! There are eight bits in a byte, so to translate from one to the other, you can multiply or divide by eight. For example, if you want to transfer 1MB across a 1Mbps connection it will take eight seconds.

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