What is the difference between KB and KiB?

KB (kilobyte) uses the SI decimal standard where 1 KB = 1000 bytes. KiB (kibibyte) uses the binary standard where 1 KiB = 1024 bytes. The IEC introduced the KiB notation in 1998 to eliminate ambiguity, but many systems still use "KB" to mean 1024 bytes.

Why does my OS show a different file size than the file manager?

Windows uses binary units (1024) but labels them as KB/MB/GB, while macOS uses SI units (1000) for display. This causes the same file to appear different sizes across operating systems.

Which standard should I use?

Use SI (1000) for networking, storage marketing, and data transfer rates. Use binary (1024) when working with RAM, operating system file sizes, or programming contexts where memory addressing is involved.

How accurate is this converter?

Results are computed in JavaScript using 64-bit floating-point arithmetic and displayed to up to 6 decimal places, which is more than sufficient for any practical file size conversion.

Can I convert kilobytes back to bytes?

Yes. Use the swap button to flip the direction and enter a KB or KiB value to get the equivalent byte count.

Bytes to Kilobytes Converter

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

Convert bytes to kilobytes using SI (1 KB = 1000 B) or binary (1 KiB = 1024 B) standards.

Input Value

Amount

Convert from

Results

Enter a value and click Convert to see results.

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Summary

Convert bytes to kilobytes using SI (1 KB = 1000 B) or binary (1 KiB = 1024 B) standards.

How it works

Enter any byte value in the input field.
The converter instantly calculates the SI result: bytes divided by 1000.
It also calculates the binary result: bytes divided by 1024.
Results are displayed to up to 6 significant decimal places.
Use the copy buttons to grab either value for your work.
Click the swap button to enter a kilobyte value and convert back to bytes.

Use cases

Understand file size differences reported by Windows vs. macOS.
Convert network transfer metrics from bytes to kilobytes.
Clarify storage capacity between drive manufacturers and OS reports.
Quickly check KB values when reading API documentation.
Compare SI and binary byte counts for academic or technical writing.
Validate data payloads during software development and testing.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu