File Size Conversion Table

Binary vs decimal byte prefixes — KiB vs KB, MiB vs MB, and friends.

Reference Reference Updated Apr 19, 2026
Reference

SI (decimal, 1000)

Prefix Symbol Bytes Shortform
kilobyte kB 10³ = 1 000 1 kB
megabyte MB 10⁶ = 1 000 000 1 MB
gigabyte GB 10⁹ = 1 000 000 000 1 GB
terabyte TB 10¹² = 1 × 10¹² 1 TB
petabyte PB 10¹⁵ 1 PB
exabyte EB 10¹⁸ 1 EB

IEC (binary, 1024)

Prefix Symbol Bytes SI equivalent
kibibyte KiB 2¹⁰ = 1 024 1 000 × 1.024 kB
mebibyte MiB 2²⁰ = 1 048 576 ~ 1.049 MB
gibibyte GiB 2³⁰ = 1 073 741 824 ~ 1.074 GB
tebibyte TiB 2⁴⁰ ~ 1.1 TB
pebibyte PiB 2⁵⁰ ~ 1.126 PB
exbibyte EiB 2⁶⁰ ~ 1.153 EB

Bits vs bytes

1 byte
8 bits
1 kbit/s
1 000 bits/second (network)
1 KiB/s
1 024 bytes/second
Disk manufacturer marketing
uses SI (1 TB = 10¹² bytes)
OS reporting
often uses IEC (1 TiB = 2⁴⁰ bytes)

Notes

  • A 1 TB disk advertises 1 × 10¹² bytes. Your OS may display ~931 GiB — same bytes, different prefix.
  • Network speeds are in bits/s (Mbps). File transfers in bytes/s (MB/s). Divide Mbps by 8 for MB/s.

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