1 Mbit = ? bytes

Question

I always get confused about this. Is there a "standard" conversion of Megabits to bytes?

Is it:

 1 Megabit == 1,000,000 bits == 125,000 bytes

Or:

 1 Megabit == 2^20 bits == 1,048,576 bits == 131,072 bytes

The wonderful thing about standards is that there are so many to choose from. — Robᵩ, Apr 28 '11 at 20:39
@Rob pretty much nails it. Both are widely-used. Strictly speaking, `Mega` etc. are SI prefixes and stand for powers of ten, but many many millions of people don't give a damn about that. — , Apr 28 '11 at 20:44
Side note: often when talking of Kbits/Mbits the number is "gross", not taking in account protocol overhead. The conversion to useful bytes may be different from a simple division by 8. — 6502, Apr 28 '11 at 21:31

score 24 · Accepted Answer · edited Apr 28 '11 at 21:21

24

Megabits is a unit of measure that comes from TELECOM, not CS. So it is:

 1 Megabit == 1,000,000 bits == 125,000 bytes

When it's a CS based unit of measure, usually the 1024 rules apply:

 1 Megabyte = 1,024 Kilobytes = 1,024 x 1,024 bytes

edited Apr 28 '11 at 21:21

vichle

2,499
1
15
17

answered Apr 28 '11 at 20:38

Pablo Santa Cruz

176,835
32
241
292

2

Also, the unit **Mebibyte** (MiB) is now used for binary-based values (*1024 rules*) versus the now SI approved base-10 **Megabyte**. All but Microsoft uses the new unit meanings in their operating systems. – Andrew Moore Apr 28 '11 at 21:23
@Pablo Santa Cruz Now I'm confused. [Google disagrees with you.](http://www.google.com/search?q=megabit%20to%20byte) - it says "1 megabit = 131 072 byte". I know nothing about this, so I might just have misunderstood. – Dan Blows Apr 29 '11 at 16:04
@Blowski: Don't know where you get that Google says that 1 muegabit = 131072 bytes. But check out wiki: http://en.wikipedia.org/wiki/Megabit – Pablo Santa Cruz Apr 29 '11 at 19:52
@Blowski: The number 125,000 comes from 1,000,000/8. 1 bytes = 8 bits. – Pablo Santa Cruz Apr 29 '11 at 19:53
@Pablo Santa Cruz I put the link above - it's just searching on Google for `megabit to byte` and Google Calculator returns "1 megabit = 131 072 byte". I'm not saying you're wrong - just trying to clear up a discrepancy between Google and Wikipedia. I suspect they're both right, referring to different things, but to the lay man it looks like they disagree. – Dan Blows Apr 30 '11 at 00:03
google tells me 1 MBit = 131072 bytes see: https://www.google.com/search?q=1+megabit+to+byte – Chris Apr 04 '14 at 13:44
When I click your search link I get 1 MBit = 125000 bytes from Google. – Joshua Nov 18 '20 at 15:27

PleaseStand · Answer 2 · 2011-04-28T21:32:50.817

One megaoctet (only the same as a megabyte if each byte has eight bits) is eight megabits. Exactly the same conversion applies as for megabytes.

A one "megabit" RAM, ROM, or flash memory chip has 1024² mebibits (Mibit) = 1 048 576 bits.
A one megabit per second Internet connection can transfer 1000² megabits (Mbit) = 1 000 000 bits per second.

So four different conversions of "megabits" to "megabytes" may apply (assuming that each byte does have eight bits):

1 Mibit (mebibit) = 8 MiB (mebibytes) = 8 388 608 B = 8.388608 MB (megabytes)
1 Mbit (megabit) = 8 MB (megabytes) = 8 000 000 B ≈ 7.6294 MiB (mebibytes)

score 1 · Answer 3 · answered Mar 02 '17 at 18:14

Kilo is 1.000, Mega is 1.000.000 times of whatever it is. Such as Kilogram is 1.000 gram. Kilohertz is 1.000 hertz so on.

Same for Mega, MegaHertz is 1.000.000 hertz, Megabit is 1.000.000 bit.

Since 1 byte is 8 bit, then 1.000.000 / 8 = 125.000 byte.

When it comes to computer, the multiplier changes slightly, such as Kilo is 1024 times and Mega is 1024*1024 = 1.048.576 times of whatever it is (in generally bit).

In this case 1 MegaBit = 1.024 * 1.024 = 1.048.576 bits, in terms of byte 1.048.576/8 = 131.072 bytes.

score 1 · Answer 4 · answered Apr 28 '11 at 20:40

1

It's the former.

http://en.wikipedia.org/wiki/Megabit

answered Apr 28 '11 at 20:40

myeeshen

114
6

Google says 1 Megatbit = 1.049e+6 bits – Koray Tugay Jan 25 '14 at 09:43

CenterOrbit · Answer 5 · 2011-05-20T19:57:42.370

1

1 megabit = 0.125 megabyte

google it

Alright, I didn't mean for my answer to cause such uproar, but as all of your comments are valid, I figured I would come back to help clear up my reputation a bit.

I believe the correct answer to the whole question is that a

Megabit is 1,000,000 Bits
Mebibit is 1,048,576 Bits
Megabyte is 8,000,000 Bits
Mebibyte is 8,388,608 Bits

So the original question is not a matter of which one is correct, but that they have the wrong name to the label.

1 Megabit == 2^20 bits == 1,048,576 bits == 131,072 bytes

Should instead be:

1 Mebibit == 2^20 bits == 1,048,576 bits == 131,072 bytes

edited May 20 '11 at 19:57

answered Apr 28 '11 at 20:43

CenterOrbit

6,446
1
28
34

2

This wonderfully puts off the question 1000 vs 1024 by ignoring it! – David Zimmerman Apr 28 '11 at 20:45
This answer states: `1 Megabit == 131,072 bytes` – Nate Apr 28 '11 at 20:56
2

-1 he clearly searched before and is asking a very specific and valid question. No need for the google link here. – Aleadam Apr 28 '11 at 21:26
1 Didn't answer what was a pretty reasonable question. – Dan Blows Apr 29 '11 at 16:00
..and I have changed my mind about your answer as it seems to muddy the waters on the accepted answer. – Dan Blows Apr 30 '11 at 00:05

dispatcher · Answer 6 · 2015-08-02T19:06:29.720

https://wiki.ubuntu.com/UnitsPolicy

UNIT POLICY. this is new unit policy for all 2 base and 10 base units

The binary meanings are more commonly used in relation to solid-state memory (such as RAM)

while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks."

for more innformation see

https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Dates_and_numbers#Quantities_of_bytes_and_bits

score 0 · Answer 7 · answered Apr 28 '11 at 20:41

While there is a movement to introduce Mebi and the like as the measurement for the power of two units, the usage isn't universial or accepted. However, from experience, bits are most likely to be depicted with the normal definition of Mega, so 1,000,000 bits.

Nate · Answer 8 · 2012-03-07T14:30:38.360

0

It may vary by industry. Component manufacturers offering FLASH products advertise their products as "1Mbit" and contain "131,072 bytes". (Reference: SST's 1 Mbit SPI Bus Serial FLASH (PDF Datasheet); indexable addresses 0h-1FFFFh)

edited Mar 07 '12 at 14:30

answered Apr 28 '11 at 20:52

Nate

18,892
27
70
93

1 Mbit = ? bytes

8 Answers8