Last updated: February 05, 2025

MB to KB Converter

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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.

SI Prefixes
International System of Units (SI) prefixes

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.

Binary Prefixes for Byte

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.

Definition and value of megabyte (MB)
Definition of megabyte and its values.

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

$$\text{N}_\text{KB} = \text{N}_\text{MB} \times 1{,}000$$

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

$$\text{N}_\text{KiB} = \text{N}_\text{MiB} \times 1{,}024$$

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:

$$\text{N}_\text{KB} = \text{N}_\text{MB} \times 1{,}000$$
$$\text{N}_\text{KB} = 8.3 \times 1{,}000 = \boxed{8,300 \text{ KB}}$$

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.

Convert 8.3 megabytes to kilobytes example
Convert 8.3 megabytes to kilobytes using our calculator.

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:

$$\text{N}_\text{KiB} = \text{MiB} \times 1{,}024$$
$$\text{N}_\text{KiB} = 8.3 \times 1{,}024 = \boxed{8,499.2 \text{ KiB}}$$

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.

Convert 8.3 mebibytes to kibibytes example
Convert 8.3 mebibytes to kibibytes using our calculator.

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

MegabytesKilobytes
0.1 MB100 KB
0.5 MB500 KB
1 MB1,000 KB
2 MB2,000 KB
4 MB4,000 KB
5 MB5,000 KB
10 MB10,000 KB
20 MB20,000 KB
30 MB30,000 KB
40 MB40,000 KB
50 MB50,000 KB
60 MB60,000 KB
70 MB70,000 KB
80 MB80,000 KB
90 MB90,000 KB
100 MB100,000 KB
200 MB200,000 KB
500 MB500,000 KB
800 MB800,000 KB
1,000 MB1,000,000 KB
Megabytes to kilobytes conversion table

Binary (IEC) prefixes

MebibytesKibibytes
0.1 MiB102.4 KiB
0.5 MiB512 KiB
1 MiB1,024 KiB
2 MiB2,048 KiB
4 MiB4,096 KiB
5 MiB5,120 KiB
10 MiB10,240 KiB
20 MiB20,480 KiB
30 MiB30,720 KiB
40 MiB40,960 KiB
50 MiB51,200 KiB
60 MiB61,440 KiB
70 MiB71,680 KiB
80 MiB81,920 KiB
90 MiB92,160 KiB
100 MiB102,400 KiB
200 MiB204,800 KiB
500 MiB512,000 KiB
800 MiB819,200 KiB
1000 MiB1,024,000 KiB
Mebibytes to kibibytes conversion table

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.

MB to KB Converter

About this app

MB to KB Converter

The megabyte to kilobyte (MB to KB) converter is a simple tool for converting data storage between megabytes (MB) and kilobytes (KB), with explanations, formulas, examples, and tables.

Availability

You can use the calculator for free as a PWA web app online or install it locally on any modern operating system, including Android, iOS, Windows 11/10, and macOS.

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References

2 Sources

  1. ⬆️ ⬆️ Metric (SI) Prefixes | NIST, NIST, Jan. 13, 2010.

    https://www.nist.gov/pml/owm/metric-si-prefixes
  2. ⬆️ ⬆️ IEC 60027-2 Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics.

    https://webstore.iec.ch/en/publication/30633