In this article, we’ll show you how to convert data from megabytes (MB) to kilobytes (KB). We will cover essential definitions, provide examples, share relevant formulas, and present tables, along with answers to common questions.
Definitions of KB and MB
Let’s get started by understanding the key definitions and differences between Kilobyte
and Megabyte
. Understanding these terms will allow you to perform conversions confidently.
What is a Kilobyte (KB)?
A kilobyte (KB
) is a unit of measurement for data storage used to measure files or memory that are small in size, typically under one million bytes.
It has symbols or abbreviations such as KB
, Kbyte
, KiB
, or Kibyte
.
When using International System of Units (SI) prefixes[1], which are based on powers of 10, a kilobyte (KB) equals 1,000 bytes (1 KB = 103 = 1,000 B
).
The table below shows all the SI prefixes and the associated symbols, multipliers, and colloquial.

When using International Electrotechnical Commission (IEC) binary prefixes[2], which are based on powers of 2, a kilobyte (KB) equals 1,024 bytes (1 KB = 210 = 1,024 B
)
The IEC defined a set of binary prefixes to avoid confusion with the decimal-based SI prefixes. The table below shows all the binary prefixes, associated symbols, and its multipliers.

Here is a comparison between the binary and SI prefixes for data storage:
1 KB = 103 = 1,000 B
1 KiB = 210 = 1,024 B
For general communication, you can use SI prefixes as they are familiar with the metric system, while for more accurate contexts, you should use IEC binary prefixes.
What is a Megabyte (MB)?
A megabyte (MB
) is a unit of measurement for data storage used to measure files or memory that are large in size, typically between one million and one billion bytes.
It has symbols or abbreviations such as MB
, Mbyte
, MiB
, or Mibyte
.

When using International System of Units (SI) prefixes[1], which are based on powers of 10, a megabyte (MB) equals 1,000,000 bytes.
1 MB = 103 KB = 1,000 KB
1 MB = 106 B = 1,000,000 B
When using International Electrotechnical Commission (IEC) binary prefixes[2], which are based on powers of 2, a megabyte (MB) equals 1,048,576 bytes.
1 MiB = 210 KiB = 1,024 KiB
1 MiB = 220 B = 1,048,576 B
MB to KB formula
Let’s take a closer look at the conversion formula so you can carry out these conversions independently, whether using a calculator or doing it manually with pencil and paper.
Using decimal (SI) prefixes
The kilo-
prefix in the International System of Units (SI) represents a multiplier of 103 (1,000)
and mega-
represents a multiplier of 106 (1,000,000)
.
So, to convert from megabytes to kilobytes, multiply the number of megabytes (NMB
) by 1,000
.
NKB = NMB × 103 = NMB × 1,000
Or remember the MB-to-KB
conversion factor: 1 MB = 1,000 KB
Using binary (IEC) prefixes
The kibi-
prefix in the International Electrotechnical Commission (IEC) represents a multiplier of 210 (1,024)
and mebi-
represents a multiplier of 220 (1,048,576)
.
So, to convert from mebibytes to kibibytes, multiply the number of mebibytes (NMiB
) by 1,024
.
NKiB = NMiB × 1,024
Or remember the MiB-to-KiB
conversion factor: 1 MiB = 1,024 KiB
Examples
Now, let's take a look at an example that illustrates the calculations required to convert from megabytes to kilobytes (MB to KB)?
Example
Sarah is a graphic designer working on a project, and she needs to send a high-resolution image file to her client. The file size is 8.3 megabytes (MB), but the client’s email server has a limit of 12,000 kilobytes (KB) per attachment. To ensure the file doesn’t exceed the limit, she decides to convert the file size from megabytes to kilobytes to check if it’s within the allowed size.
To determine the image file size in kilobytes, we will convert using decimal and binary units to avoid any differences when compared with the file limit.
Option 1: Using decimal (SI) prefixes
Since 1 megabyte (MB) equals 1,000 kilobytes (KB), we can convert 8.3 MB to kilobytes by using the following formula:
So, the 8.3 MB image file, when expressed in decimal units, is equivalent to 8,300 KB
.
Alternatively, you can use our calculator by entering 8.3
into the MB box, and you instantly get the storage value in kilobytes, in this case, 8,300 KB
.

Option 2: Using binary (IEC) prefixes
Since 1 mebibyte (MiB) equals 1,024 kibibytes (KiB), we can convert 8.3 mebibytes
to kibibytes by using the following formula:
So, the 8.3 MiB image file, when expressed in binary units, is equivalent to 8,499.2 KiB
.
Alternatively, you can use our calculator by choosing MiB and entering 8.3
into the From box, choose KiB from the To unit box, and you instantly get the storage value in tebibytes, in this case, 8,499.2 KiB
.

Thus, the 8.3 MB image file is equivalent to 8,300 KB in decimal form or 8,499.2 KB in binary form, which is under the file limit. Therefore, Sarah can confidently send the attachment.
MB to KB conversion table
The conversion table below provides a handy reference for converting data storage capacity from megabytes (MB) to kilobytes (KB). It covers a range from 0.1 MB to 1,000 MB, allowing for easy and quick conversions between these units of measurement.
Decimal (SI) prefixes
Megabytes | Kilobytes |
---|---|
0.1 MB | 100 KB |
0.5 MB | 500 KB |
1 MB | 1,000 KB |
2 MB | 2,000 KB |
4 MB | 4,000 KB |
5 MB | 5,000 KB |
10 MB | 10,000 KB |
20 MB | 20,000 KB |
30 MB | 30,000 KB |
40 MB | 40,000 KB |
50 MB | 50,000 KB |
60 MB | 60,000 KB |
70 MB | 70,000 KB |
80 MB | 80,000 KB |
90 MB | 90,000 KB |
100 MB | 100,000 KB |
200 MB | 200,000 KB |
500 MB | 500,000 KB |
800 MB | 800,000 KB |
1,000 MB | 1,000,000 KB |
Binary (IEC) prefixes
Mebibytes | Kibibytes |
---|---|
0.1 MiB | 102.4 KiB |
0.5 MiB | 512 KiB |
1 MiB | 1,024 KiB |
2 MiB | 2,048 KiB |
4 MiB | 4,096 KiB |
5 MiB | 5,120 KiB |
10 MiB | 10,240 KiB |
20 MiB | 20,480 KiB |
30 MiB | 30,720 KiB |
40 MiB | 40,960 KiB |
50 MiB | 51,200 KiB |
60 MiB | 61,440 KiB |
70 MiB | 71,680 KiB |
80 MiB | 81,920 KiB |
90 MiB | 92,160 KiB |
100 MiB | 102,400 KiB |
200 MiB | 204,800 KiB |
500 MiB | 512,000 KiB |
800 MiB | 819,200 KiB |
1000 MiB | 1,024,000 KiB |
FAQs
Is 1 kilobyte or 1 megabyte larger?
A megabyte (MB) is a thousand times bigger than a kilobyte (KB). Here are the relationships between the units:
Decimal prefixes
1 MB = 1,000 KB
1 KB = 1 ÷ 1,000 = 0.001 MB
Binary prefixes
1 MiB = 1,024 KiB
1 KiB = 1 ÷ 1,024 = 0.0009765625 MiB
How to convert from megabyte to kilobyte?
To convert data storage from megabytes (MB) to kilobytes (KB), follow these simple steps based on the standard you are using:
- Write down the data storage value in
megabytes (MB)
.
Decimal (SI) prefixes
- Multiply it by the value of a
MB-to-KB
conversion factor:1,000
. - The result from multiplication is the value of the data storage in
kilobytes (KB)
.
Binary (IEC) prefixes
- multiply it by the value of a
MiB-to-KiB
conversion factor:1,024
. - The result from multiplication is the value of the data storage in
kibibytes (KiB)
.
You now know how to convert data storage capacity from megabytes (MB) to kilobytes (KB). You can quickly use our calculator to convert between the data storage units to save time for future calculations.
For further understanding, check our data storage converter page to learn more about the differences between decimal and binary units of data storage.