KB to MB Converter
Kilobytes, Megabytes & Gigabytes
Decimal (1 KB = 1000 B)
Binary (1 KiB = 1024 B)
The 1024 vs. 1000 Controversy
Converting Kilobytes to Megabytes should be easy, right? It's just moving a decimal point. Unfortunately, in the computer world, there are two completely different ways to do this math.
It depends on who you ask:
- Hard Drive Makers (Decimal): They say 1 KB = 1,000 Bytes. This makes their drives look bigger on the box.
- Windows Operating System (Binary): It says 1 KB = 1,024 Bytes. This is mathematically correct for binary computing ($2^{10}$).
Understanding "KiB" vs "KB"
To solve this confusion, a new naming standard was invented (IEC 60027-2), but it is rarely used by the general public.
| Unit | Name | Size (Bytes) | Used By |
|---|---|---|---|
| KB | Kilobyte | 1,000 | Mac OS, Drive Packaging |
| KiB | Kibibyte | 1,024 | Windows, RAM |
| MB | Megabyte | 1,000,000 | Mac OS, Drive Packaging |
| MiB | Mebibyte | 1,048,576 | Windows, RAM |
The "Shrinking" Hard Drive:
If you buy a "500 GB" hard drive, the box uses Decimal math (500,000,000,000 bytes).
When you plug it into Windows, it divides that number by 1024 three times (once for KB, once for MB, once for GB).
Result: Windows reports the drive as only 465 GB. You didn't lose space; it's just a different language!
If you buy a "500 GB" hard drive, the box uses Decimal math (500,000,000,000 bytes).
When you plug it into Windows, it divides that number by 1024 three times (once for KB, once for MB, once for GB).
Result: Windows reports the drive as only 465 GB. You didn't lose space; it's just a different language!
Common File Sizes (Reference)
When converting data, it helps to know what these numbers look like in the real world.
- 1 KB (Kilobyte): A very short email (text only).
- 1 MB (Megabyte): A high-quality JPEG photo or 1 minute of MP3 music.
- 1 GB (Gigabyte): About 1 hour of SD video or 200 music tracks.
- 1 TB (Terabyte): 500 hours of HD video or 250,000 photos.
Which Setting Should You Use?
Use "Binary (1024)" if you are trying to figure out if a file will fit on your Windows computer or a USB stick.
Use "Decimal (1000)" if you are calculating network transfer speeds (Mbps) or buying a hard drive based on the box label.