What is a mebibyte (MiB)?

A mebibyte is exactly 1,048,576 bytes (1024 × 1024). The name "mebi" comes from "mega binary," defined by IEC 80000-13 to give the 2²⁰-byte unit an unambiguous name, separate from the decimal megabyte (1,000,000 bytes). RAM and most operating systems use the 1,048,576-byte definition.

How do I convert mebibytes to bytes?

Multiply the MiB value by 1,048,576. For example, 4 MiB × 1,048,576 = 4,194,304 bytes. For fractional MiB values the result may not be a whole number.

What is the difference between MiB and MB?

1 MiB (mebibyte, IEC binary) = 1,048,576 bytes. 1 MB (megabyte, SI decimal) = 1,000,000 bytes. Storage manufacturers use the decimal definition; operating systems and RAM chips traditionally use the binary one. IEC introduced MiB in 1998 to make the distinction explicit and prevent confusion.

Why do operating systems report memory in MiB?

Memory chips are built in powers of two, so binary units (KiB, MiB, GiB) align perfectly with hardware boundaries. Linux, Windows, and macOS all report RAM and process memory in binary units because the hardware is binary.

Is the conversion exact?

Yes for integer MiB inputs. Since 1 MiB = 1,048,576 bytes by definition, the multiplication is exact. Fractional inputs use JavaScript 64-bit floating-point arithmetic, accurate to 15–16 significant digits.

Mebibytes to Bytes Converter

Name: Mebibytes to Bytes Converter
Availability: InStock
Author: Nham Vu

Enter a mebibyte (MiB) value and instantly see the exact byte count using the IEC binary standard where 1 MiB = 1,048,576 bytes.

Enter Mebibytes

Mebibytes (MiB)

MiB vs MB — what is the difference?

1 MiB (mebibyte, binary) = 1,048,576 bytes

1 MB (megabyte, decimal) = 1,000,000 bytes

IEC 80000-13 introduced "MiB" to give the binary 1,048,576-byte unit an unambiguous name, distinct from the decimal megabyte used by storage manufacturers.

Result

Enter a MiB value and click Convert.

Common MiB to Bytes Reference

MiB	Bytes (× 1,048,576)	MB (× 1,000,000)	Common size

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Summary

Enter a mebibyte (MiB) value and instantly see the exact byte count using the IEC binary standard where 1 MiB = 1,048,576 bytes.

How it works

Enter any number of mebibytes in the input field.
The converter multiplies by 1,048,576 to produce the exact byte count (IEC binary standard).
A secondary result shows the equivalent in megabytes (MB) using the SI decimal standard (× 1,000,000) for comparison.
The reference table lists common MiB values alongside their exact byte equivalents.
Copy any result with the copy button.

Use cases

Find the exact byte count of a 256 MiB memory allocation for embedded or systems programming.
Convert MiB values reported by Linux tools like free, df, or /proc/meminfo into bytes.
Translate network buffer sizes from MiB to bytes for low-level protocol configuration.
Verify that a file size reported in MiB matches an expected byte count.
Clarify the MiB vs MB distinction when writing technical documentation or specs.
Calculate precise byte lengths for binary file format headers or memory maps.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu