MB to Mbit Converter
Enter megabytes and the equivalent in megabits appears instantly, rounded to four decimals. By default 1 MB counts as 1,048,576 bytes; tick the SI box to use 1,000,000.
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Created by the Reeliy Editorial Team. Last updated: Oct 19, 2026
How many megabits are in a megabyte?
A byte is eight bits, so in pure SI terms 1 MB = 8 Mbit. The converter's default is slightly different. It counts a megabyte the way an operating system does, as 1,048,576 bytes (8,388,608 bits), while a megabit stays at the decimal 1,000,000 bits used in telecommunications. That gives 1 MB = 8.388608 Mbit. Ticking Use SI standard removes the binary megabyte and returns the clean factor of 8.
SI: Mbit = MB × 8
default: Mbit = MB × 8 × 1.048576 = MB × 8.388608
The mixed default mirrors common practice: file sizes are often reported in binary units, whereas the amount of data on a communication link is counted in decimal bits.
Difference between MB and Mbit
Both measure an amount of data, not a speed. MB (megabyte) is the unit for file sizes and storage. Mbit (megabit) is one eighth of a megabyte in SI terms and is the unit that network rates are built on. The capital B for byte and lowercase b for bit is the whole difference on paper, and it is easy to misread.
When time enters the picture the units become Mbps and MB/s. Those are handled by the MB to Mbps converter, which uses the same factors.
How to convert MB to Mbit
- Enter the size in megabytes.
- Leave Use SI standard clear to multiply by 8.388608, or tick it to multiply by 8.
- Read the size in megabits.
The answer is rounded to four decimal places and has no thousands separators.
Example: a 25 MB file
Default factor: 25 × 8.388608 = 209.7152 Mbit. SI factor: 25 × 8 = 200 Mbit. If you then send that file over a link that carries 50 Mbit every second, the ideal transfer time is 200 ÷ 50 = 4 seconds in SI counting, or 209.7152 ÷ 50 ≈ 4.19 seconds with the binary megabyte. Real transfers are slower because of protocol overhead; the download time calculator lets you estimate that more fully.
MB to Mbit conversion table
| Megabytes (MB) | Megabits, default (× 8.388608) | Megabits, SI (× 8) |
|---|---|---|
| 0.5 | 4.1943 | 4 |
| 1 | 8.3886 | 8 |
| 2 | 16.7772 | 16 |
| 5 | 41.943 | 40 |
| 10 | 83.8861 | 80 |
| 25 | 209.7152 | 200 |
| 50 | 419.4304 | 400 |
| 100 | 838.8608 | 800 |
| 250 | 2,097.152 | 2,000 |
| 500 | 4,194.304 | 4,000 |
| 1,000 | 8,388.608 | 8,000 |
Common mistakes
- Reading MB as Mbit. A 25 MB file is not 25 megabits; it is eight times as many bits.
- Using 8.388608 for a figure that is already decimal. If a size was given in SI megabytes, tick the SI box so the factor is exactly 8.
- Writing Mb for both units. Some sources use Mb for megabit and MB for megabyte, others are careless. Check the capitalisation, or the context, before converting.
To work the other way, use the Mbit to MB converter. For smaller building blocks, see the bytes to bits converter.
Frequently asked questions
How many megabits are in one megabyte?
8 in SI terms. With the converter's default binary megabyte (1,048,576 bytes) the figure is 8.388608, shown as 8.3886.
Why does the default answer for 1 MB read 8.3886 and not 8?
The default counts the megabyte as 1,048,576 bytes but the megabit as 1,000,000 bits. Tick Use SI standard to get exactly 8.
Is MB the same as Mb?
No. A capital B means byte and a lowercase b means bit, so Mb (megabit) is one eighth of an MB (megabyte) in SI terms.
Is this the same as converting MB/s to Mbps?
The factors are identical, but MB/s and Mbps include time. Use the MB to Mbps converter when you are working with speeds.
References
Cite this converter and page
If you use this page in your work, you can cite it as:
Reeliy Editorial Team. (2026). MB to Mbit Converter. Reeliy. https://reeliy.com/converters/convert-mb-to-mbit“MB to Mbit Converter.” Reeliy, 2026, https://reeliy.com/converters/convert-mb-to-mbit.