Byte size converter
Convert between digital storage units: bytes, KB, MB, GB, TB and their IEC binary equivalents
Input
Base
SI (decimal, base-1000)
IEC (binary, base-1024)
TL;DR
What is Byte size converter?
Digital storage size conversion translates between units used to measure data: bytes, kilobytes, megabytes, gigabytes, terabytes, and their binary (IEC) equivalents. There are two competing definitions: SI decimal (1 KB = 1,000 bytes) and IEC binary (1 KiB = 1,024 bytes), which frequently causes confusion.
Common use cases
- ‣Storage comparison: convert a file size to understand whether it fits within a platform limit (e.g. email attachment, S3 object size)
- ‣Network throughput: convert MB/s to Mbps (megabits per second) for bandwidth calculations (1 MB/s = 8 Mbps)
- ‣Cloud billing: cloud providers often bill in GB; convert to understand actual storage costs
Frequently asked questions
Why does my 1 TB hard drive show as 931 GB in Windows?
Hard drive manufacturers use SI decimal (1 TB = 1,000,000,000,000 bytes). Windows reports size in binary units but incorrectly labels them GB instead of GiB. 1,000,000,000,000 bytes = 931.3 GiB (binary gibibytes). The drive is not smaller than advertised; the label is inconsistent.
What is the difference between KB and KiB?
KB (kilobyte) in SI decimal equals 1,000 bytes. KiB (kibibyte) in IEC binary equals 1,024 bytes. The IEC prefixes (KiB, MiB, GiB, TiB) were introduced in 1998 specifically to remove this ambiguity. Memory (RAM) is measured in binary units; storage and network speeds are typically in decimal.