Kilobytes to Megabytes (kB to MB)
1 kilobyte equals 0.001 megabytes exactly.
How to convert kilobytes to megabytes
To convert kilobytes to megabytes, multiply the number of kilobytes by 0.001. This factor is exact. To go the other way, multiply megabytes by 1,000.
megabytes = kilobytes × 0.001
Example: 10 kilobytes = 0.01 megabytes.
Decimal prefixes (kB, MB, GB) are powers of 1,000; binary prefixes (KiB, MiB, GiB) are powers of 1,024. Storage makers use decimal; Windows reports binary but labels it GB.
About these units
Kilobyte (kB)
1,000 bytes in the SI (decimal) definition. Older software and Windows sometimes use KB to mean 1,024 bytes; see kibibyte.
Few units have had two meanings for so long. By the mid-1960s most computers used binary addressing, so memory sizes came in powers of two and engineers borrowed kilo to mean 1,024. IBM documentation for the System/360 in 1964 used an uppercase K for 1,024. Hard disk makers took a different path from the start. The IEC later settled the question: kilobyte, symbol kB, means 1,000 bytes, and 1,024 bytes is a kibibyte.
Floppy disks show the muddle. The Shugart SA-400 of 1976 held 109,375 bytes unformatted and was advertised as 110 Kbyte, the decimal way, while a 1978 Tandon double-density disk held 368,640 bytes, or 360 times 1,024, and was sold as 360 KB. Windows still divides by 1,024, so a 65,536-byte file appears as 64 KB there, while Mac OS X Snow Leopard and later would call it 66 kB. A kilobyte is also tiny: Edgar Allan Poe's The Cask of Amontillado is 12,843 bytes.
1 kilobyte = 1,000 bytes (exactly).
Sources: Wikipedia: Kilobyte; Wikipedia: Binary prefix; NIST: Prefixes for binary multiples
Megabyte (MB)
1,000,000 bytes (decimal). A typical MP3 song is 3–5 MB; a smartphone photo is 2–5 MB.
Megabyte started out as informal jargon. Base-1,024 usage grew because 1,024 is close to 1,000 and convenient for binary multiples. In 1999 the IEC standardized binary prefixes, assigning megabyte to 10 to the sixth bytes and mebibyte to 2 to the twentieth. By the end of 2009 the IEEE, the EU, ISO and NIST had adopted that standard, though the word still carries different meanings in practice.
The famous 1.44 MB floppy disk is a mixed case: it counts 1,024,000 bytes per megabyte, and it actually holds 1,474,560 bytes. Today most storage media and networking use the decimal definition, while Windows uses the binary one for memory such as RAM. For scale, a PlayStation 2 memory card held 8 MB, the plain text of Moby Dick runs to 1.192 MB, and one megabyte holds about one minute of 128 kbit/s MP3 audio.
1 megabyte = 1,000,000 bytes (exactly).
Sources: Wikipedia: Megabyte; NIST: Prefixes for binary multiples
Related conversions
- Megabytes to kilobytes (reverse)
- Kilobytes to bytes
- Kilobytes to gigabytes
- Kilobytes to terabytes
- Kilobytes to bits
- Kilobytes to petabytes
- Kilobytes to kibibytes
- Kilobytes to mebibytes
- Kilobytes to gibibytes
- Kilobytes to tebibytes
- Kilobytes to kilobits
- Kilobytes to megabits
- Kilobytes to gigabits
- Bytes to megabytes
- Gigabytes to megabytes
- Terabytes to megabytes
- Bits to megabytes
- Petabytes to megabytes
- Kibibytes to megabytes
- Mebibytes to megabytes
- Gibibytes to megabytes
- Tebibytes to megabytes
- Kilobits to megabytes
- Megabits to megabytes
- Gigabits to megabytes
See all digital storage units.