Bytes to KB Converter

• KB = bytes ÷ 1,000 (decimal / SI standard)
• KiB = bytes ÷ 1,024 (binary / IEC standard)
• Windows displays binary but labels it with the decimal name — the source of most confusion
• A perfectly round result on the binary divisor means the original number was binary
• The converter above handles every unit from bits to quettabytes

Frequently Asked Questions

How many bytes are in 1 KB?

1,000 bytes in a decimal kilobyte (KB, SI standard), or 1,024 bytes in a binary kilobyte (KiB). File systems and older software often say 'KB' while computing with 1,024 — if a 2,048-byte file shows as exactly '2 KB', the tool is using binary.

Is 1024 bytes 1 KB or 1.02 KB?

Both, depending on the definition: 1024 bytes is exactly 1 KiB (binary) and 1.024 KB (decimal). The IEC introduced the KiB/MiB/GiB names in 1998 precisely to end this ambiguity — but everyday labeling still mixes them.

Why is my email attachment limit measured differently?

Mail providers commonly state limits in decimal MB but enforce them on the encoded message size — and Base64 encoding inflates attachments by about 33%+ on top of the KB/KiB question. A '25 MB' limit realistically fits about 18 MB of raw files.

Does this converter handle other units too?

Yes — the tool above converts between bits, bytes, KB, MB, GB, TB and beyond, in both decimal and binary systems, and includes transfer-time and storage-cost estimates.