Convert Mbps to MB/s and back, plus every bit and byte rate either side. See what your connection really delivers and how long real files take.
The decimal column is simply the advertised figure divided by eight. The binary column is what a download manager reporting MiB/s shows for the same connection — 4.9% smaller again, because it counts 1,048,576 bytes to the megabyte instead of 1,000,000. Neither tool is wrong; they are two different megabytes.
| Connection | Advertised (Mbps) | Decimal (MB/s) | Binary (MiB/s) |
|---|---|---|---|
| Entry-level broadband | 25 | 3.125 | 2.98 |
| Standard broadband | 50 | 6.25 | 5.96 |
| Fast broadband | 100 | 12.5 | 11.921 |
| Gigabit fibre | 1,000 | 125 | 119.209 |
| USB 3.0 link | 5,000 | 625 | 596.046 |
| 10 Gigabit Ethernet | 10,000 | 1,250 | 1,192.093 |
You might also find these calculators useful
Internet plans are sold in megaBITS per second and computers report downloads in megaBYTES per second. There are eight bits in a byte, so the two figures differ by a factor of eight — and that single factor is behind most of the “my internet is slower than I paid for” confusion there is. Enter a speed in either unit and this converter gives you the other, every unit in between, and how long real files actually take.
A bit is one binary digit and a byte is eight of them. Networks have always been measured in bits per second because that is what the wire carries; files are measured in bytes because that is how storage is addressed. Converting is one division: MB/s = Mbps ÷ 8. The subtlety is that some software reports MEBIbytes per second — 1,048,576 bytes rather than 1,000,000 — which is a further 4.9% smaller again, and this converter offers both so you can see which one your download manager is showing you.
Conversion formula
A test in Mbps and a download manager in MB/s are the same measurement eight times apart. Convert before concluding you are being short-changed.
Turn a link rate into the byte rate that decides how long a copy takes, then take it to the transfer-time calculator.
SSDs and drives are rated in MB/s, networks in Mbps. One conversion puts them on the same axis.
Work out whether the MiB/s on screen is the best your connection can do, or whether something else is the limit.
Mbps and MBps differ by one lowercase letter and a factor of eight. Advertising uses the first, your operating system uses the second, and almost nobody says which.
MB/s and MiB/s are 4.9% apart. If your download manager reports MiB/s, dividing the advertised speed by eight still leaves you short of its number, and nothing on screen explains why.
A speed test reports the link rate in Mbps. A file copy reports delivered bytes after protocol overhead. Converting the units is the first step; the rest is overhead.
Divide by eight to go from the advertised figure to megabytes per second. Multiply by eight to go the other way. Everything else on this page is that same rule at different magnitudes.
0.125 MB/s — one eighth, because a byte is eight bits. The question is usually asked the other way round, though: a 100 Mbps connection downloads at up to 12.5 MB/s, a 500 Mbps connection at 62.5 MB/s, and a gigabit connection at 125 MB/s. Those are ceilings, not promises; protocol overhead and congestion take a further few percent off in practice.
Two reasons stack. First, many tools report MEBIbytes per second (MiB/s), which are 1,048,576 bytes rather than 1,000,000 — 4.9% smaller for the same real speed, so 12.5 MB/s reads as 11.92 MiB/s. Second, the advertised rate is the link rate; TCP and IP headers alone cost about 2.7% at a standard 1500-byte MTU, before congestion or server limits. Convert to MiB/s on this page to see whether the two figures actually agree.
No, and the capital letter is the whole difference. Mbps is megabits per second, the unit internet plans are sold in. MBps or MB/s is megabytes per second, the unit file transfers are reported in. One MBps is eight Mbps. Writing Mb for megabit and MB for megabyte is the convention, but it is followed inconsistently enough that it is worth checking the context rather than the capitalisation.
Netflix publishes 15 Mbps for 4K, which is 1.875 MB/s. Converting is the easy half; the harder part is that the figure is per stream, so a household watching two 4K streams at once needs 30 Mbps of it available at the same time. The bandwidth calculator on this site adds those up properly.
Because that is what the physical layer moves. A wire or a radio carries one symbol at a time and the bit is the natural unit for it, which is why every networking standard from Ethernet to Wi-Fi is specified in bits per second. Storage is addressed in bytes, so file sizes and transfer progress are reported that way. Neither side is going to change, so the factor of eight is permanent.