Data Transfer Rate Converter
Convert data transfer rates between bits per second and bytes per second at every scale. Internet plans are sold in megabits and download managers report megabytes, which differ by a factor of eight — the single most common reason a 100 Mbps connection appears to download at only 12 MB/s.
Converters
Private by default
This tool runs entirely in your browser. Your data is never uploaded to a server.
How it works
Eight bits to the byte
MB/s = Mbit/s ÷ 8 · transfer time ≈ file size ÷ rate
Network engineers count bits and file systems count bytes, and a byte is eight bits. Every conversion here is that factor of eight combined with the usual decimal prefixes, so a 400 Mbit/s link moves 50 MB every second.
- The lowercase b means bits and the uppercase B means bytes: 100 Mb/s and 100 MB/s differ by a factor of eight.
- Network prefixes are decimal — 1 Mbit/s is exactly 1,000,000 bit/s, not 1,048,576.
- Real throughput runs a few percent below the theoretical figure because packet headers, retransmissions, and encryption all travel over the same link.
- Wi-Fi and mobile speeds are shared and variable; the advertised rate is a ceiling, not a guarantee.
For reference
Connection speed and a 5 GB download
| Plan | MB/s | Time for 5 GB |
|---|---|---|
| 25 Mbit/s | 3.13 | 26 min 40 s |
| 100 Mbit/s | 12.5 | 6 min 40 s |
| 300 Mbit/s | 37.5 | 2 min 13 s |
| 500 Mbit/s | 62.5 | 1 min 20 s |
| 1 Gbit/s | 125 | 40 s |
Times assume a 5 GB file (5,000 MB) and the full advertised rate. Expect a few percent longer in practice.
How to use
4 clear steps.
Enter the speed figure from your plan or download manager.
Select its unit — note that Mbit/s and MB/s are different entries.
Select the unit you need and read the converted rate.
Use the table to estimate how long a large file will take.
Good to know
Frequently asked questions
- How many MB/s is 100 Mbps?
- 12.5 MB/s. There are 8 bits in a byte, so divide the megabit figure by 8. Real transfers land slightly below this because of protocol overhead.
- Why does my 1 Gbps plan download at 118 MB/s?
- 1 Gbps is 125 MB/s in theory. TCP/IP headers, encryption, and the server's own limits typically cost a few percent, so 110–120 MB/s is a healthy result rather than a fault.
- Is this different from the Data Size Converter?
- Yes. This one converts speeds — bits and bytes per second. The Data Size Converter handles fixed amounts of storage such as MB, GB, and GiB. Speed is the size divided by time.