Mbps to MB/s converter

A byte is eight bits, so Mbps divided by eight is MB/s. The reason it causes so much trouble is that the two are distinguished only by letter case: lowercase b for bit, uppercase B for byte. It is the only unit in everyday use where capitalisation changes the value by 800%, and it is why a 100 Mbps connection shows 12.5 MB/s in a download manager and generates a support call.

The convention is not arbitrary. Network engineering counts bits because that is what travels on the wire, and serial links historically sent more than eight bits per byte once framing was included. Storage and files count bytes because that is the addressable unit. Both are correct in their own domain and they meet, awkwardly, in a download progress bar.

One further wrinkle: network units are strictly decimal. A megabit is 1,000,000 bits, never 1,048,576 — the binary prefixes belong to storage, and even there the correct names are mebibyte and gibibyte. So converting Mbps to MB/s is a clean divide by eight with no binary correction, and any tool that applies 1024 somewhere in that chain is wrong.

The monthly figure is worth a look if you have a data cap. A 100 Mbps connection running flat out for a month moves about 32 TB, which puts most caps in perspective — they are limits on typical use, not on capacity.