system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can ISP's get away with saying your download & upload speeds are extremely high during speedtests, but never actually meet these speeds?

I'm just curious how this practice of promising 40mb+ download speeds, only to have the actual figure closer to 4mb is an acceptable practice.

Edit: Thanks for the replies, I see the issue is Mb is different from MB. I still find getting 40Mb with fiber optic to be disgusting but do realise I am getting what I paid for.
gpt
>promising 40mb+ download speeds, only to have the actual figure closer to 4mb

You need to pay **very** close attention to the capitalization of the units being used there.  "M**b**ps" and "M**B**ps" are totally different things.

When you see a lower-case 'b', that means "bits" (a value that can be either 1 or 0).  When you see an upper-case 'B', that means "Bytes", which is (almost always) a value composed of 8 bits.

So a 40 Mbps connection is exactly the same as a 5 MBps connection.