Thursday, 15 September 2016

File Sizes

  • A File size is the measure of space a file takes on a storage medium or memory device such as a computer hard drive, memory cards,pen drives etc.
  • File size is basically measured in bits or bytes.
  • Bit: A bit is value of either 0 or 1.
  • Byte: One byte is equal to the 8 bits(1 Byte = 8 bits).

Different File Sizes:

NameSymbolSizeNumber of BytesEqual to
KiloByteKB
2^10
1,024
1024 B
MegaByteMB
2^20
1,048,576
1024 KB
GigaByteGB
2^30
1,073,741,824
1024 MB
TeraByteTB
2^40
1,099,511,627,776
1024 GB
PetaBytePB
2^50
1,125,899,906,842,624
1024 TB
ExaByteEB
2^60
1,152,921,504,606,846,976
1024 PB
ZettaByte
ZB
2^70
1,180,591,620,717,411,303,424
1024 EB
YottaByteYB
2^80
1,208,925,819,614,629,174,706,176
1024 ZB

Limitations of File Sizes:
  • File sizes are limited by the file system that is used and its implementation. Here are details on the common file systems: 
FAT16FAT32NTFS
Maximum File Size2^32 - 1 Bytes2^32 - 1 Bytes2^64 bytes - 1 KB (On disk format)
2^44 bytes - 64 KB (Implementation)
Maximum Volume Size4 GB32 GB2^64 allocation units (On disk format)
2^32 allocation units (Implementation)
Files per Volume2^162^222^32 - 1
  • NTFS stands for "New Technology File System ".
  • FAT stands for "File Allocation Table".
Examples for File Sizes: