How this calculator works
An Mbps figure is a rate in megabits per second, not megabytes per second. Internet and network providers quote bit rates, while a file manager reports file sizes in bytes, so the two numbers differ by a factor of eight before any prefix conversion. The megabit uses the SI decimal meaning of mega, one million bits. A megabyte is eight megabits, and a mebibyte is 8,388,608 bits. Dividing a rate in Mbit/s by 8 gives MB/s, which is the number to compare with a download progress bar.
Formula
bits per second = value x F(unit), where F is the number of bits per second in one unit. 1 Mbit/s = 1,000,000 bit/s, 1 Gbit/s = 1,000,000,000 bit/s, 1 MB/s = 8,000,000 bit/s and 1 MiB/s = 8,388,608 bit/s. MB/s = Mbit/s / 8. MiB/s = Mbit/s x 1,000,000 / 8,388,608.
Worked example
100 Mbit/s is 0.1 Gbit/s, 100,000 kbit/s and exactly 12.5 MB/s. It is 11.9209 MiB/s. A 1 Gbit/s connection reaches at most 125 MB/s, or about 119.2 MiB/s, before overhead.
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Frequently asked questions
Why is my 100 Mbps connection slower than 100 MB per second?
100 Mbps means 100 megabits per second, which is 12.5 megabytes per second. That is the raw rate; protocol overhead and Wi-Fi conditions usually reduce the real download speed further.
Do network speeds use decimal or binary prefixes?
Network rates use decimal SI prefixes: 1 Mbit/s is one million bits per second. Binary prefixes such as MiB are more common for file and memory sizes, so this page labels both.
How long does a 1 GB file take at 100 Mbps?
One GB is 1,000,000,000 bytes or 8,000,000,000 bits. At 100,000,000 bits per second that is 80 seconds at the raw rate, before overhead.