MB to KB Converter

How to convert MB to KB

To convert MB to KB, multiply by 1000. 2 MB is 2,000 KB, and 0.5 MB is 500 KB. If you're matching a number from Windows File Explorer, multiply by 1024 instead: 2 MB is 2,048 KB there.

This comes up when a form gives its limit in MB but your phone or PC shows file sizes in KB. Convert the limit to KB, compare, and you know straight away whether the file needs compressing.

MB to KB formula

• Decimal: KB = MB x 1000
• Binary: KiB = MiB x 1024

Example: 1.5 MB x 1000 = 1,500 KB. In binary, 1.5 x 1024 = 1,536 KiB.

Why are there two answers: 1000 or 1024?

Computers count in powers of two, so early on a kilobyte was taken to mean 1,024 bytes. Standards bodies later fixed the prefixes to their usual meaning, kilo for 1,000, and added separate names for the binary units: KiB, MiB and GiB. Drive makers, network figures and macOS use the decimal units. Windows File Explorer still divides by 1024 but prints KB, MB and GB.

That's why a 1 TB drive shows about 931 GB in Windows. Nothing is missing; it's the same number of bytes counted two ways. For a longer explanation, read how many KB are in a MB and how many MB are in a GB.

File too big for an upload limit?

If the conversion shows your file is over the limit, shrink it to a set size instead of guessing. Image Compressor takes photos down to a target such as 50 KB or 200 KB, and Compress PDF does the same for documents. Aim slightly under the limit, for example 190 KB for a 200 KB cap, so the file passes whichever way the site counts.