What is the difference between KiB and KB?

KiB (kibibyte) is a binary unit: 1 KiB = 1,024 bytes. KB (kilobyte) is a decimal unit: 1 KB = 1,000 bytes. The IEC standardized the KiB prefix in 1998 to eliminate the ambiguity of "kilobyte," which some systems used to mean 1,024 bytes and others used to mean 1,000 bytes.

How do I convert kibibytes to kilobytes?

Multiply the KiB value by 1.024. For example: 100 KiB × 1.024 = 102.4 KB. Equivalently, multiply by 1024 then divide by 1000.

Is 1 KiB larger or smaller than 1 KB?

1 KiB is larger. It equals 1,024 bytes, while 1 KB equals only 1,000 bytes. So 1 KiB = 1.024 KB.

Why does Windows show sizes in "KB" but actually uses 1,024 bytes?

Windows historically labeled binary units with the SI names (KB, MB, GB) instead of the IEC names (KiB, MiB, GiB). So Windows "KB" means 1,024 bytes — technically a kibibyte. This labeling quirk is why a file's Windows size can differ from what web or Linux tools report.

When would I need to convert KiB to KB?

Common cases: comparing OS-reported file sizes (often binary KiB) with ISP or storage-vendor specs (decimal KB); converting RAM or cache sizes between notations; reading documentation that mixes IEC and SI prefixes.

Kibibytes to Kilobytes Converter

Name: Kibibytes to Kilobytes Converter
Availability: InStock
Author: Nham Vu

Convert kibibytes (KiB, binary: 1 KiB = 1,024 bytes) to kilobytes (KB, decimal: 1 KB = 1,000 bytes) instantly.

Kibibytes to Kilobytes

1 KiB = 1,024 bytes → KB = KiB × 1024 / 1000

Kibibytes (KiB) Kilobytes (KB)

Kilobytes to Kibibytes

1 KB = 1,000 bytes → KiB = KB × 1000 / 1024

Kilobytes (KB) Kibibytes (KiB)

Conversion Formulas

KiB → KB

KB = KiB × 1024 / 1000

= KiB × 1.024

KB → KiB

KiB = KB × 1000 / 1024

= KB × 0.9765625

Common Values

Kibibytes (KiB)	Kilobytes (KB)
1 KiB	1.024 KB
10 KiB	10.24 KB
100 KiB	102.4 KB
500 KiB	512 KB
1,000 KiB	1,024 KB
1,024 KiB	1,048.576 KB

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Summary

Convert kibibytes (KiB, binary: 1 KiB = 1,024 bytes) to kilobytes (KB, decimal: 1 KB = 1,000 bytes) instantly.

How it works

Enter a value in the Kibibytes (KiB) field to convert to kilobytes (KB).
The converter multiplies KiB by 1.024 to get the KB result.
Use the second panel to convert from kilobytes back to kibibytes (divide KB by 1.024).
Results update instantly as you type, showing up to 10 significant digits.
Click Copy next to any result to copy the number to your clipboard.

Use cases

Convert OS-reported file sizes (KiB) to KB for use in documentation.
Reconcile storage device specs (KB) with what a file manager displays (KiB).
Translate memory sizes between IEC and SI notation in technical specs.
Check why an OS shows a different size than what a manufacturer advertises.
Understand the IEC vs SI binary prefix distinction when reading storage benchmarks.
Cross-verify values from tools that mix KiB and KB notation.

Frequently Asked Questions

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