1024 bytes equals to 1 KB.
After all, "kilo" means 1000. In most cases, this approximation is fine for determining how much space a file takes up or how much disk space you have. But there are really 1024 bytes in a kilobyte. The reason for this is because computers are based on the binary system.
So in actuality, one KB is really 1024 bytes, not 1000. ... One megabyte is 1024 x 1024 bytes. 1024 kilobytes is called one Megabyte. So one kilobyte is actually 1024 bytes, and 1024 of those is (1024 x 1024) 1048576 bytes. In short, one Megabyte is really 1,048,576 bytes.
Therefore 1KB is the same as 1024 x 8 = 8192 binary digits. Gigabyte (GB): There are 1024MB in one gigabyte. Hard drive manufacturers have long eschewed this system in favour of rounding down to make things easier (and also provide less storage space).