MB to KB Converter — Megabytes to Kilobytes
An MB to KB converter multiplies megabytes into kilobytes — useful when a tool demands kilobytes while your source material is measured in megabytes.
Quick answer: Multiply by 1,024 for binary kilobytes or by 1,000 for decimal kilobytes. 2 MB is 2,048 KB (binary) or 2,000 KB (decimal) — a 2.4% gap that grows with size.
The two lines are the same file — only the definition of “GB” differs. This 2.4% gap per step is why a 1 TB drive shows 931 GiB in Windows.
| MB | KB |
|---|---|
| 0.5 | 512 |
| 1 | 1,024 |
| 2 | 2,048 |
| 5 | 5,120 |
| 10 | 10,240 |
| 50 | 51,200 |
| 100 | 102,400 |
| 500 | 512,000 |
| 1,000 | 1,024,000 |
| Binary | 1 MB = 1,024 KB = 1,048,576 bytes |
|---|---|
| Decimal | 1 MB = 1,000 KB = 1,000,000 bytes |
| 10 MB | 10,240 KB (binary) or 10,000 KB (decimal) |
| Reality check | A 5 MB photo is 5,120 KB binary — over half a 10 MB attachment limit |
When databases and limits speak KB
Site builders, forums and older APIs often cap uploads in kilobytes: 512 KB avatars, 1,536 KB attachment bins, 2 MB scans. Multiplying your source size by 1,000 (or 1,024) tells you the real number the server will measure — essential when a 4.8 MB photo is rejected by a “5 MB” limit because the server counted 4,915,200 bytes against 5,000,000.
Planning compressed assets
Web performance budgets are often written in KB: 200 KB of hero imagery, 50 KB of CSS, 30 KB of icons. Converting from MB back to KB keeps the arithmetic simple: a 1.2 MB hero is 1,228 KB binary, so it blows a 200 KB budget by six times and should be re-encoded as WebP or AVIF.
When to use this calculator
- Meeting a kilobyte-based upload cap with a megabyte-sized photo.
- Translating a performance budget written in KB into the MB your exports show.
- Filling in forms that ask for file size in KB only.
- Comparing compression results between tools using different units.