One MB (megabyte) is equal to eight Mb (megabit). So, 1Mbps (megabit per second) is equal to 0.125MBps (megabyte per second).
MB refers to a mega byte , while Mbps refers to mega bits per second. A megabyte is equal to eight megabits. Megabits per second (Mbps) are always used when referring to Wi-Fi speeds.
You would use megabytes per second (MB/s) to refer to the rate at which data could be transferred to a storage device. 100Mbps (megabits per second) is considered an average download speed for internet service. In fact, it’s the bare minimum to meet the FCC’s definition of broadband internet speed .
However, 100Mbps upload speed would be considered very fast -- the FCC’s minimum requirement for upload speed is only 20Mbps..
Technology
Megabits vs. Megabytes: What You Need to Know

Both are units of digital information, but they have big differences when it comes to internet speeds.