Mbps vs MBps: Megabits vs Megabytes per Second
Mbps means megabits per second. MBps (also written MB/s) means megabytes per second. One byte is 8 bits, so 1 MBps = 8 Mbps. To turn an internet speed in Mbps into the download speed your browser shows in MB/s, divide by 8. A 100 Mbps connection downloads at most about 12.5 MB/s.
The only difference in writing is a small “b” or a capital “B”, which is why so many people think their internet is eight times slower than they paid for. Below is a conversion table, how long common downloads take, and a real test we ran to show the numbers in practice. To find your own speed in Mbps, run our free internet speed test.
Megabits per second vs megabytes per second
| Mbps | MBps (MB/s) | |
|---|---|---|
| Stands for | Megabits per second | Megabytes per second |
| Unit letter | Lowercase b (bit) | Capital B (byte) |
| Size of one unit | 1,000,000 bits | 1,000,000 bytes = 8,000,000 bits |
| Where you see it | Internet plans, speed tests, routers | Browser downloads, Steam, file copy windows |
| Convert | Mbps ÷ 8 = MB/s | MB/s × 8 = Mbps |
Bits are the smallest unit of data, a single 0 or 1. Bytes are groups of 8 bits, and file sizes are measured in bytes. Network speeds have long been measured in bits per second, while files are measured in bytes. That is why your provider sells “500 Mbps” but your browser shows “62 MB/s”.
“Mega” means one million. The US National Institute of Standards and Technology (NIST) defines 1 megabyte (MB) as 1,000,000 bytes. It uses a different name, the mebibyte (MiB), for 1,048,576 bytes (2 to the power of 20).
Mbps to MB/s conversion table
The times below are the best case: the full speed, with nothing else using the connection. Real downloads take a little longer, because part of every connection is used to manage the data on its way.
| Internet speed | Top download speed | 1 GB file | 5 GB file | 50 GB game |
|---|---|---|---|---|
| 10 Mbps | 1.25 MB/s | 13 min 20 sec | 1 hr 7 min | 11 hr 7 min |
| 25 Mbps | 3.1 MB/s | 5 min 20 sec | 26 min 40 sec | 4 hr 27 min |
| 50 Mbps | 6.25 MB/s | 2 min 40 sec | 13 min 20 sec | 2 hr 13 min |
| 100 Mbps | 12.5 MB/s | 1 min 20 sec | 6 min 40 sec | 1 hr 7 min |
| 300 Mbps | 37.5 MB/s | 27 sec | 2 min 13 sec | 22 min 13 sec |
| 500 Mbps | 62.5 MB/s | 16 sec | 1 min 20 sec | 13 min 20 sec |
| 1,000 Mbps (1 Gbps) | 125 MB/s | 8 sec | 40 sec | 6 min 40 sec |
Here 1 GB means 1,000 MB, the decimal way disk makers and Apple count.
How to work it out yourself: time in seconds = file size in MB × 8 ÷ speed in Mbps. For a 2,000 MB file on a 40 Mbps line: 2,000 × 8 ÷ 40 = 400 seconds, or about 6 minutes 40 seconds.
A real test: the same download, three different numbers
We downloaded a test file of exactly 20,000,000 bytes from Cloudflare’s speed test server in a browser on 11 November 2026, and timed it.
- It took 30.58 seconds.
- In bits: 20,000,000 × 8 = 160,000,000 bits ÷ 30.58 s = 5.23 Mbps. This is the kind of number a speed test shows.
- In bytes: 20,000,000 ÷ 30.58 s = 0.654 MB/s. This is the kind of number a download window shows. It is exactly 5.23 ÷ 8.
- In Windows: we saved a file of exactly 20,000,000 bytes on a Windows 11 PC, and File Explorer listed its size as “19.0 MB”.
Why does Windows say 19.0 and not 20? Windows counts file sizes in units of 1,024 × 1,024 bytes (what NIST calls a mebibyte), but still labels them “MB”. 20,000,000 ÷ 1,048,576 = 19.07, which Windows shows as 19.0 MB. Disk makers, and newer versions of Apple’s macOS and iOS, use 1,000,000 bytes, as Apple explains. That is also why a new “1 TB” drive shows up as about 931 GB in Windows.
So a single download can be described as 5.23 Mbps, 0.654 MB/s or about 0.62 “MB/s” in Windows-style units, and all three are right.
How to check your speed in both units
- Open our Internet Speed Test and press Start speed test.
- Note your download speed in Mbps when it finishes.
- Divide it by 8 to get the most you can expect in MB/s in a browser or game store.
- Compare that with what your download window shows. If the download window shows much less than Mbps ÷ 8, the problem is usually the server you are downloading from, Wi-Fi, or other devices using the line, not the units.
For example, our tool measured about 6.5 Mbps on the same connection, which is a top download speed of about 0.8 MB/s. That matches the 0.654 MB/s download above, since speeds on that line varied between tests.
Other units you will see
| Unit | Meaning | Equal to |
|---|---|---|
| kbps or Kbps | Kilobits per second | 1,000 bits per second |
| Mbps | Megabits per second | 1,000 kbps |
| Gbps | Gigabits per second | 1,000 Mbps |
| KB/s | Kilobytes per second | 8 kbps |
| MB/s or MBps | Megabytes per second | 8 Mbps |
| MiB/s | Mebibytes per second | 1,048,576 bytes per second, about 8.39 Mbps |
Some programs show MiB/s, or use binary units but label them “MB/s”. If a number looks about 5% lower than you expect, that is a likely reason.
Common questions
Is 100 Mbps the same as 100 MB/s? No. 100 Mbps is 12.5 MB/s, eight times less. To download at a true 100 MB/s you need an 800 Mbps connection, plus a server and device fast enough to keep up.
Why does my provider use Mbps? Network speeds are traditionally measured in bits per second. Speed tests use Mbps too, so you can compare your result directly with your plan.
Is a capital or small “b” important? Yes. “Mb” is megabits and “MB” is megabytes. When you see “MBps” or “MB/s”, it means bytes.
Summary
- Mbps = megabits per second (internet speed). MB/s = megabytes per second (download speed).
- Divide Mbps by 8 to get MB/s. 100 Mbps ≈ 12.5 MB/s.
- Windows labels sizes in 1,024-based units, so a 20,000,000-byte file shows as 19.0 MB.
To find out what your connection really delivers, test your internet speed, then see our guide to what a good internet speed is.