What is a kibibyte (KiB)?

A kibibyte is exactly 1024 bytes. The name comes from "kibi" (binary kilo), defined by IEC 80000-13 to remove ambiguity between decimal kilobytes (1000 bytes) and binary kilobytes (1024 bytes). Most operating systems and memory chips use the 1024 definition.

What is the difference between KB and KiB?

1 KB (kilobyte, SI/decimal) = 1000 bytes. 1 KiB (kibibyte, IEC binary) = 1024 bytes. Storage manufacturers use KB/MB/GB with SI values; operating systems historically use the same labels but with binary (1024) values. The IEC introduced KiB/MiB/GiB to make the distinction explicit.

How do I convert bytes to kibibytes?

Divide the byte count by 1024. For example, 2048 bytes ÷ 1024 = 2 KiB. For non-power-of-two values, the result will be a decimal number.

Why does my OS show a file as smaller than the advertised size?

Storage manufacturers label capacity in decimal (1 GB = 1,000,000,000 bytes). Your OS reports in binary (1 GiB = 1,073,741,824 bytes), so the same drive appears smaller. The data is all there — it is a units difference, not a data loss.

Is this converter exact?

Yes. Since 1 KiB is defined as exactly 1024 bytes, division is exact for integer byte counts. Fractional results use JavaScript 64-bit floating-point, which is accurate to 15-16 significant digits.

Bytes to Kibibytes Converter

Enter a byte value and instantly see the equivalent in kibibytes (KiB) using the IEC binary standard where 1 KiB = 1024 bytes exactly.

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Bytes (B)

KB vs KiB — what is the difference?

1 KB (kilobyte, decimal) = 1,000 bytes

1 KiB (kibibyte, binary) = 1,024 bytes

Operating systems traditionally use the 1024 definition. IEC 80000-13 introduced "KiB" so the binary unit has an unambiguous name.

Result

Enter a byte value and click Convert.

Common Byte to KiB Reference

Bytes	KiB (÷ 1024)	KB (÷ 1000)	Common size

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Summary

A kibibyte (KiB) is exactly 1024 bytes — a binary unit defined by IEC 80000-13. This differs from a kilobyte (KB), which storage manufacturers define as 1000 bytes. The discrepancy matters: a file reported as 512 KB by an OS (binary) is actually 512 KiB (524,288 bytes), not 512,000 bytes. This tool converts any byte count to KiB with full precision, and shows the difference from the SI kilobyte for quick comparison.

How it works

Enter any number of bytes in the input field.
The converter divides by 1024 to produce the kibibyte value (binary, IEC standard).
A secondary result shows kilobytes (KB) using the SI decimal standard (÷ 1000) for comparison.
The reference table lists common byte counts alongside their exact KiB equivalents.
Copy any result using the copy button.

Use cases

Understand why a "512 KB" file shown by your OS actually contains 524,288 bytes.
Convert memory sizes from bytes to KiB for embedded systems or kernel documentation.
Translate network buffer sizes from bytes to KiB for configuration files.
Check file sizes in KiB when comparing against IEC-standard storage specs.
Clarify the KB vs KiB distinction in technical writing or documentation.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu