File size converter
Convert any file size between bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. Shows all units simultaneously. Toggle between decimal (SI) and binary (IEC) standards.
Decimal (SI): 1 KB = 1,000 B · 1 MB = 1,000,000 B · used by storage manufacturers
How it works
All unit conversions use pure JavaScript arithmetic. No library required. Decimal (SI) conversions divide by powers of 1000; binary (IEC) conversions divide by powers of 1024. Results update instantly as you type.
Processing runs in your browser
All calculations happen locally in the page. Our servers are not involved at any point.
Related operations
For converting between binary, hex, and decimal values, try the number base converter. To convert between length, mass, and other units, use the unit converter. For computing file hashes alongside size checks, see the hash generator.
Frequently asked questions
- What units does this converter support?
- Decimal: B, KB, MB, GB, TB, PB. Binary: B, KiB, MiB, GiB, TiB, PiB. Select a unit from the dropdown and enter a value to see all conversions at once.
- What is a petabyte?
- 1 PB (petabyte, decimal) = 1,000,000,000,000,000 bytes = 1000 TB. 1 PiB (pebibyte, binary) = 2^50 bytes ≈ 1.126 PB. Petabytes are used to describe large data centres and cloud storage.
- How do I convert GB to MB?
- Multiply by 1000 (decimal) or 1024 (binary). For example, 2.5 GB = 2500 MB (decimal) or 2560 MiB (binary).
- How do I convert MB to KB?
- Multiply by 1,000 in decimal units (1 MB = 1,000 KB) or by 1,024 in binary units (1 MiB = 1,024 KiB). For example, 3.5 MB is 3,500 KB, and 3.5 MiB is 3,584 KiB.
Last reviewed September 30, 2026
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