Megabytes (MB) to Kilobytes (KB) Converter

File sizes here use the decimal (SI) system, the same one drive makers and network providers use. In that system 1 Megabyte is 10⁶ bytes and 1 Kilobyte is 10³ bytes. Divide one by the other and you get the ratio between the two units: 10⁶ ÷ 10³ = 10³.

Megabyte is the bigger unit, so you multiply. Every MB holds 1,000 KB, which means the decimal point moves 3 places to the right.

These two sit side by side on the ladder (B → KB → MB → GB → TB → PB → EB → ZB → YB → RB → QB), so there is nothing to work out beyond remembering that every step is a factor of 1,000.

Need the other direction? Open the KB to MB converter.

A megabyte is 1,000 kilobytes, about a minute of MP3 audio at 128 kbps. Megabytes are what you see on photos, PDFs, songs and slide decks, and they sit behind most email attachment and upload limits.

A kilobyte is 1,000 bytes, roughly a short paragraph of text. Kilobytes are the everyday unit for small files such as text documents, icons, config files and scripts, and for tight limits like form uploads or email signatures.

Going from megabytes down to kilobytes always gives a bigger number, because the unit you land on is smaller. It is the usual direction when a limit or a form asks for a smaller unit than the one you have in mind.