File Size Converter
Calculators & Converters
Convert between bytes, KB, MB, GB, TB, and PB. Toggle between binary (1 KiB = 1024 B) and decimal (1 kB = 1000 B) prefixes.
Runs entirely in your browserAbout File Size Converter
File size units are a source of constant confusion because two competing standards co-exist. The binary system (KiB, MiB, GiB) uses powers of 1024 and is used internally by operating systems. The decimal system (kB, MB, GB) uses powers of 1000 and is used by hard drive manufacturers and the SI standard. The difference grows with scale: 1 KiB is only 2.4% bigger than 1 kB, but 1 TiB is about 10% bigger than 1 TB. That 10% is exactly why a '1 TB' drive shows up as about 931 GB in your file manager.
This converter takes any byte count and shows it in all six common units (bytes through petabytes) simultaneously, in either binary or decimal mode. It's a fast reference for sizing files, network throughput, RAM, disk space, or anything else measured in bytes. The per-row copy buttons let you grab any individual unit value. Everything runs in your browser.
How to use
- 1
Enter a byte count
Type the raw byte value into the input.
- 2
Pick a mode
Binary (KiB/MiB/GiB) for OS-internal measurements. Decimal (kB/MB/GB) for hard drive sizes and SI-standard measurements.
- 3
Read all six units
The table shows the value in bytes, KB/KiB, MB/MiB, GB/GiB, TB/TiB, and PB/PiB. Each row has a Copy button.
Examples
1,500,000 bytes in binary mode
Output
1,500,000 B = 1,464.84 KiB = 1.43 MiB = 0.0014 GiB1 TB (decimal) in binary units
Demonstrates the famous storage discrepancy.
Output
1,000,000,000,000 B (1 TB decimal) = 931.32 GiBFrequently asked questions
What's the difference between KiB and KB?+
KiB (kibibyte) is exactly 1024 bytes (IEC 80000-13 standard). KB (often used to mean kilobyte) usually means 1000 bytes in SI but is often confused. Some software uses KB to mean 1024 — the convention varies. KiB is unambiguous.
Which mode should I use?+
Binary for OS-internal measurements (file sizes shown by your file manager, RAM, etc.). Decimal for hard drive sizes, network throughput, and SI-compliant measurements.
Why does my hard drive show less space than advertised?+
Hard drive manufacturers advertise in decimal (TB = 1,000,000,000,000 bytes). Your OS reports in binary (TiB = 1,099,511,627,776 bytes). A '1 TB' drive is only 0.91 TiB by binary measurement, which looks like 'missing' space.
Are KB and kB the same?+
Strictly, kB (lowercase k) is the SI form meaning exactly 1000 bytes. KB (capital K) is non-standard but commonly used to mean either 1000 or 1024 bytes depending on context. KiB removes the ambiguity by clearly meaning 1024.
Is anything sent to a server?+
No. Conversion is local — just division by the appropriate power of 1024 or 1000.
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