Megabits to Megabytes
A byte is eight bits, so one megabit is one eighth of a megabyte: divide megabits by 8 to get megabytes. A 100 Mbps connection moves at most 12.5 MB per second, and a 1 Gbps line 125 MB per second.
1 megabit = 0.125 megabytes
1 Mb = 0.125 MB · divide by 8
Lowercase b, uppercase B
Internet providers sell speed in megabits per second, written Mbps or Mb/s with a lowercase b. Browsers, game launchers and file managers show download progress in megabytes per second, MB/s with a capital B. The two look almost identical and differ by a factor of eight, which is why a 300 Mbps plan never shows 300 in a download window; its ceiling is 37.5 MB/s.
Network speeds are always decimal: 1 Mbps is 1,000,000 bits per second, not 1,048,576. If a download dialog uses binary megabytes, the shown figure drops by another 4.6%, so a perfect 100 Mbps line reads about 11.9 MiB/s.
Megabits to megabytes conversion table
Rounded to six significant digits. Change any value in the converter above for an exact figure.
| Megabits (Mb) | Megabytes (MB) |
|---|---|
| 1 | 0.125 |
| 2 | 0.25 |
| 3 | 0.375 |
| 4 | 0.5 |
| 5 | 0.625 |
| 6 | 0.75 |
| 7 | 0.875 |
| 8 | 1 |
| 9 | 1.125 |
| 10 | 1.25 |
| 12 | 1.5 |
| 15 | 1.875 |
| 20 | 2.5 |
| 25 | 3.125 |
| 30 | 3.75 |
| 40 | 5 |
| 50 | 6.25 |
| 60 | 7.5 |
| 70 | 8.75 |
| 75 | 9.375 |
| 80 | 10 |
| 90 | 11.25 |
| 100 | 12.5 |
| Megabytes (MB) | Megabits (Mb) |
|---|---|
| 1 | 8 |
| 2 | 16 |
| 3 | 24 |
| 4 | 32 |
| 5 | 40 |
| 6 | 48 |
| 7 | 56 |
| 8 | 64 |
| 9 | 72 |
| 10 | 80 |
| 12 | 96 |
| 15 | 120 |
| 20 | 160 |
| 25 | 200 |
| 30 | 240 |
| 40 | 320 |
| 50 | 400 |
| 60 | 480 |
| 70 | 560 |
| 75 | 600 |
| 80 | 640 |
| 90 | 720 |
| 100 | 800 |
How to convert megabits to megabytes
MB = Mb ÷ 8
1 Mb = 0.125 MB
25 Mb ÷ 8 = 3.125 MB
- Start with the value in megabits.
- Divide it by 8, which is the same as multiplying by 0.125.
- Round the result to the precision the job needs: whole numbers for everyday use, more decimals for engineering or recipes.
Estimating download and upload times
Convert the speed to megabytes per second, then divide the file size by it. A 5 GB game is 5,000 MB; at 100 Mbps (12.5 MB/s) the theoretical minimum is 400 seconds, about 6 minutes 40 seconds. Protocol overhead, Wi-Fi and server limits usually cost 5–20% more, so expect closer to 7 or 8 minutes.
Uploads are often the bottleneck. Many cable and DSL plans have upload speeds a tenth of the download speed or less, so a 20 Mbps upstream sends 2.5 MB per second, and a 400 MB video takes nearly three minutes. Shrinking a clip with compress video to 10 MB turns that into a few seconds.
Other places bits show up
Video and audio bitrates are also in bits: a 4K stream at 16 Mbps uses 2 MB every second, or 7.2 GB per hour. The bits to bytes page goes deeper into bitrate and file size, and the unit converter includes kilobytes, gigabytes and terabytes for everything else.
Frequently asked questions
- Is 100 Mbps the same as 100 MB/s?
- No. 100 Mbps is 100 megabits per second, which equals 12.5 megabytes per second. 100 MB/s would need an 800 Mbps connection.
- How long does a 1 GB download take at 50 Mbps?
- 50 Mbps is 6.25 MB/s, so 1,000 MB takes 160 seconds, a bit under three minutes, before overhead.
- Why is my download slower than my plan's advertised speed?
- Plans are quoted in megabits and as a maximum. Divide by 8 for megabytes, then allow for Wi-Fi losses, network overhead and the server's own speed limit.
- How many megabits are in one megabyte?
- Eight. Multiply megabytes by 8 to get megabits, for example 25 MB is 200 Mb.