File size - wikipedia File size Jump to : navigation , search File size is a measure of how much data a computer file contains or , alternately , how much storage it consumes . Typically , file size is expressed in units of measurement based on the byte . By convention , file size units use either a binary prefix ( as in megabyte and gigabyte ) or a metric prefix ( as in mebibyte and gibibyte ) . When a file is written to a file system , which is the case in most modern devices , it may consume slightly more disk space than the file requires . This is because the file system rounds the size up to include any unused space left over in the last disk sector used by the file . ( A sector is the smallest amount of space addressable by the file system . The size of a disk sectors is several hundred or several thousands bytes . ) The wasted space is called slack space or internal fragmentation . Although smaller sector sizes allow for denser use of disk space , they decrease the operational efficiency of the file system . The maximum file size a file system supports depends not only on the capacity of the file system , but also on the number of bits reserved for the storage of file size information . The maximum file size in the FAT32 file system , for example , is 4,294,967,295 bytes , which is one byte less than four gigabytes . Conversion table Traditional units Decimal for comparison Name IEC Binary Number of bytes Equal to Name IEC Decimal Number of bits Equal to Kibibyte KiB 1,024 1024 B Kilobit kbit 10 1,000 1000 bit Mebibyte MiB 1,048,576 1024 KiB Megabit Mbit 10 1,000,000 1000 kbit Gibibyte GiB 1,073,741,824 1024 MiB Gigabit Gbit 10 1,000,000,000 1000 Mbit Tebibyte TiB 1,099,511,627,776 1024 GiB Terabit Tbit 10 1,000,000,000,000 1000 Gbit Pebibyte PiB 1,125,899,906,842,624 1024 TiB Petabit Pbit 10 1,000,000,000,000,000 1000 Tbit Exbibyte EiB 1,152,921,504,606,846,976 1024 PiB Exabit Ebit 10 1,000,000,000,000,000,000 1000 Pbit Zebibyte ZiB 1,180,591,620,717,411,303,424 1024 EiB Zettabit Zbit 10 1,000,000,000,000,000,000,000 1000 Ebit Yobibyte YiB 1,208,925,819,614,629,174,706,176 1024 ZiB Yottabit Ybit 10 1,000,000,000,000,000,000,000,000 1000 Zbit Kilobyte ( KB ) ( JEDEC ) , is sometimes referred to unambiguously as kibibyte ( KiB ) ( IEC ) . Sometimes kB , with lower cased SI - prefix k - for kilo ( 1000 ) , is used , then always equaling 1000 bytes . A file system may display all sizes with the metric system with only kB on small files indicating it , while some file systems / operating systems would display sizes in , the traditionally used on computers , binary system for all sizes , e.g. KB , even if hard disk manufacturers may prefer to use the metric system ( for e.g. GB = 1,000,000,000 bytes and TB = 1000 GB ) , to show higher capacity numbers for their products . File transfers ( e.g. `` downloads '' ) may use rates of units of bytes ( e.g. MB / s ) in binary rather than metric system , while networking hardware , such as WiFi , always uses the metric system ( Mbits / s , Gbits / s etc . ) . of units of bits ( and it needs to send more than the files themselves , so some overhead needs to be factored in ) , making superficially similar terms very incompatible . See also ( edit ) Metric prefix Units of information References ( edit ) Jump up ^ JEDEC Solid State Technology Association ( December 2002 ) . `` Terms , Definitions , and Letter Symbols for Microprocessors , and Memory Integrated Circuits '' ( PDF ) . JESD 100B. 01 . p. 8 . Retrieved 2009 - 04 - 05 . Jump up ^ `` What is Slack Space ? '' . IT Pro. 2010 - 01 - 19 . Retrieved 2018 - 02 - 17 . Jump up ^ `` Microsoft Extensible Firmware Initiative FAT32 File System Specification , FAT : General Overview of On - Disk Format '' . Microsoft . 2000 - 12 - 06 . Retrieved 2011 - 07 - 03 . Units of information Base unit bit Platform - dependent units nibble byte syllable parcel word Platform - independent units unibit ( 1 ) dibit ( 2 ) tribit ( 3 ) quadbit ( 4 ) quartet ( 4 ) sextet ( 6 ) octet ( 8 ) hextet ( 16 ) declet ( 10 ) doublet ( 16 ) quadlet ( 32 ) octlet ( 64 ) hexlet ( 128 ) triad ( 3 ) tetrad ( 4 ) pentad ( 5 ) hexad ( 6 ) heptad ( 7 ) octad ( 8 ) slab ( 12 ) catena ( 24 ) Traditional bit units kilobit megabit gigabit terabit petabit exabit zettabit yottabit Traditional byte units kilobyte megabyte gigabyte terabyte petabyte exabyte zettabyte yottabyte IEC bit units kibibit mebibit gibibit tebibit pebibit exbibit zebibit yobibit IEC byte units kibibyte mebibyte gibibyte tebibyte pebibyte exbibyte zebibyte yobibyte Computer files Types Binary file / Text file File format List of file formats File signatures Magic number Metafile Sidecar file Sparse file Swap file System file Temporary file Zero - byte file Properties Filename 8.3 filename Long filename Filename mangling Filename extension List of filename extensions File attribute Extended file attributes File size Hidden file / Hidden directory Organisation Directory / Folder NTFS junction point Temporary folder Directory structure File sequence File system Filesystem Hierarchy Standard Path Operations Open Close Read Write Linking Alias File descriptor Hard link Shadow Shortcut Symbolic link Management File comparison File compression File manager Comparison of file managers File system permissions File transfer File sharing File verification Retrieved from `` https://en.wikipedia.org/w/index.php?title=File_size&oldid=832068145 '' Categories : Computer files Talk Read About Wikipedia Azərbaycanca Català Ελληνικά Español 한국어 Latviešu Македонски 日本 語 Русский සිංහල தமிழ் తెలుగు Tiếng Việt 中文 6 more Edit links This page was last edited on 23 March 2018 , at 17 : 00 . 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what does mb stand for in file size
File size is a measure of how much data a computer file contains or , alternately , how much storage it consumes . Typically , file size is expressed in units of measurement based on the byte . By convention , file size units use either a binary prefix ( as in megabyte and gigabyte ) or a metric prefix ( as in mebibyte and gibibyte ) . When a file is written to a file system , which is the case in most modern devices , it may consume slightly more disk space than the file requires . This is because the file system rounds the size up to include any unused space left over in the last disk sector used by the file . ( A sector is the smallest amount of space addressable by the file system . The size of a disk sectors is several hundred or several thousands bytes . ) The wasted space is called slack space or internal fragmentation . Although smaller sector sizes allow for denser use of disk space , they decrease the operational efficiency of the file system . The maximum file size a file system supports depends not only on the capacity of the file system , but also on the number of bits reserved for the storage of file size information . The maximum file size in the FAT32 file system , for example , is 4,294,967,295 bytes , which is one byte less than four gigabytes . Conversion table Traditional units Decimal for comparison Name IEC Binary Number of bytes Equal to Name IEC Decimal Number of bits Equal to Kibibyte KiB 1,024 1024 B Kilobit kbit 10 1,000 1000 bit Mebibyte MiB 1,048,576 1024 KiB Megabit Mbit 10 1,000,000 1000 kbit Gibibyte GiB 1,073,741,824 1024 MiB Gigabit Gbit 10 1,000,000,000 1000 Mbit Tebibyte TiB 1,099,511,627,776 1024 GiB Terabit Tbit 10 1,000,000,000,000 1000 Gbit Pebibyte PiB 1,125,899,906,842,624 1024 TiB Petabit Pbit 10 1,000,000,000,000,000 1000 Tbit Exbibyte EiB 1,152,921,504,606,846,976 1024 PiB Exabit Ebit 10 1,000,000,000,000,000,000 1000 Pbit Zebibyte ZiB 1,180,591,620,717,411,303,424 1024 EiB Zettabit Zbit 10 1,000,000,000,000,000,000,000 1000 Ebit Yobibyte YiB 1,208,925,819,614,629,174,706,176 1024 ZiB Yottabit Ybit 10 1,000,000,000,000,000,000,000,000 1000 Zbit Traditional units Decimal for comparison Name IEC Binary Number of bytes Equal to Name IEC Decimal Number of bits Equal to Kibibyte KiB 1,024 1024 B Kilobit kbit 10 1,000 1000 bit Mebibyte MiB 1,048,576 1024 KiB Megabit Mbit 10 1,000,000 1000 kbit Gibibyte GiB 1,073,741,824 1024 MiB Gigabit Gbit 10 1,000,000,000 1000 Mbit Tebibyte TiB 1,099,511,627,776 1024 GiB Terabit Tbit 10 1,000,000,000,000 1000 Gbit Pebibyte PiB 1,125,899,906,842,624 1024 TiB Petabit Pbit 10 1,000,000,000,000,000 1000 Tbit Exbibyte EiB 1,152,921,504,606,846,976 1024 PiB Exabit Ebit 10 1,000,000,000,000,000,000 1000 Pbit Zebibyte ZiB 1,180,591,620,717,411,303,424 1024 EiB Zettabit Zbit 10 1,000,000,000,000,000,000,000 1000 Ebit Yobibyte YiB 1,208,925,819,614,629,174,706,176 1024 ZiB Yottabit Ybit 10 1,000,000,000,000,000,000,000,000 1000 Zbit Kilobyte ( KB ) ( JEDEC ) , is sometimes referred to unambiguously as kibibyte ( KiB ) ( IEC ) . Sometimes kB , with lower cased SI - prefix k - for kilo ( 1000 ) , is used , then always equaling 1000 bytes . A file system may display all sizes with the metric system with only kB on small files indicating it , while some file systems / operating systems would display sizes in , the traditionally used on computers , binary system for all sizes , e.g. KB , even if hard disk manufacturers may prefer to use the metric system ( for e.g. GB = 1,000,000,000 bytes and TB = 1000 GB ) , to show higher capacity numbers for their products . File transfers ( e.g. `` downloads '' ) may use rates of units of bytes ( e.g. MB / s ) in binary rather than metric system , while networking hardware , such as WiFi , always uses the metric system ( Mbits / s , Gbits / s etc . ) . of units of bits ( and it needs to send more than the files themselves , so some overhead needs to be factored in ) , making superficially similar terms very incompatible .