File Size Converter
Convert between bytes, KB, MB, GB, and TB
Decimal (SI)
B
KB
MB
GB
TB
Binary (IEC)
KiB
MiB
GiB
TiB
About the File Size Converter
This tool converts between digital storage units: bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. It supports both decimal (SI) units (1 KB = 1,000 bytes) and binary (IEC) units (1 KiB = 1,024 bytes), which are the two standards used in different contexts.
Useful for comparing file sizes, understanding storage specifications, calculating how many files will fit on a drive, and translating between the units that operating systems and hardware manufacturers use. Operating systems often report in binary units while manufacturers advertise in decimal units — this converter makes the difference clear.
Frequently asked questions
Is 1 MB equal to 1,000 KB or 1,024 KB?
Both definitions exist. The decimal (SI) form treats 1 MB = 1,000,000 bytes — used by storage manufacturers and networking. The binary (IEC) form treats 1 MiB = 1,048,576 bytes — used by operating systems for RAM and file sizes.
Why does my hard drive show less space than the label says?
Manufacturers use decimal (1 TB = 10^12 bytes) but Windows reports in binary (1 TiB = 2^40 bytes). A '1 TB' drive shows up as ~931 GB in Windows — the bytes are the same, only the unit changed.