What the Data Transfer Rate Converter Does

This tool converts a data transfer rate from one unit to another: bits per second (bps), kilobits per second (kbps), megabits per second (Mbps), gigabits per second (Gbps), and megabytes per second (MB/s). Enter a value in any unit and read the equivalent in every other unit instantly.

It is useful for anyone comparing an internet plan's advertised speed to the download speed shown by a browser or app, for IT staff sizing network links, and for students learning the difference between bits and bytes. The most common reason people visit a data rate converter is the Mbps to MB/s question: why a '100 Mbps' connection downloads at roughly 12.5 MB/s.

How It Works: Bits, Bytes, and the Formula

Every conversion runs through a single base unit: bits per second. The converter first turns your input into bps, then divides into the target unit. The multipliers between bit-based units are powers of 1000 (decimal), which is the convention internet providers and networking standards use:

The one rule that trips people up is bits versus bytes. One byte equals 8 bits. Network and internet speeds are quoted in bits per second (lowercase b, as in Mbps), while file sizes and download managers usually report bytes per second (uppercase B, as in MB/s). To go from megabits to megabytes you divide by 8.

1 kbps = 1,000 bps
1 Mbps = 1,000 kbps = 1,000,000 bps
1 Gbps = 1,000 Mbps = 1,000,000,000 bps
MB/s = Mbps / 8 (and Mbps = MB/s x 8)

Worked Example: 100 Mbps to MB/s

Suppose your plan is advertised as 100 Mbps and you want the maximum theoretical download speed in megabytes per second.

Convert to bits per second: 100 Mbps x 1,000,000 = 100,000,000 bps. Then convert bits to bytes by dividing by 8: 100,000,000 / 8 = 12,500,000 bytes per second, which is 12.5 MB/s. That is why a 100 Mbps line tops out around 12.5 MB/s in a download window.

Running it the other way: a 4 GB game file at 12.5 MB/s takes about 4,000 MB / 12.5 = 320 seconds, roughly 5 minutes 20 seconds at full speed.

Practical Tips and Common Mistakes

The biggest mistake is confusing the lowercase b and uppercase B. Mbps is megabits; MB/s is megabytes. Mixing them up makes a number look eight times too fast or too slow.

Watch the case: 'Mb' or 'Mbps' means bits; 'MB' or 'MB/s' means bytes.
Real downloads run below the theoretical maximum because of protocol overhead, Wi-Fi loss, server limits, and other devices sharing the line.
Networking uses decimal units (1 Mbps = 1,000,000 bps). Some storage tools use binary units (1 MiB = 1,048,576 bytes), which is a separate distinction from bits vs bytes.
Upload and download are often different; an asymmetric plan such as 100/20 means 100 Mbps down and 20 Mbps up.

Factors That Affect Real Internet Speed

An advertised Mbps figure is a ceiling, not a guarantee. The throughput you actually get depends on the link to your provider, the equipment in your home, and conditions at the other end of the connection.

Common factors include Wi-Fi distance and interference, an aging router or network cable, the number of devices active at once, congestion during peak hours, and the speed limit imposed by the server you are downloading from. To compare a speed-test result against your plan, convert both to the same unit first; the converter handles the Mbps to MB/s step so the two numbers are directly comparable.