Megabytes to Gigabytes (MB to GB)
1 megabyte equals 0.001 gigabytes exactly.
How to convert megabytes to gigabytes
To convert megabytes to gigabytes, multiply the number of megabytes by 0.001. This factor is exact. To go the other way, multiply gigabytes by 1,000.
gigabytes = megabytes × 0.001
Example: 10 megabytes = 0.01 gigabytes.
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
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
Gigabyte (GB)
1,000,000,000 bytes (decimal). Storage manufacturers and phone makers use this definition.
The gigabyte is where the decimal-versus-binary dispute turned into lawsuits. Drive makers advertise capacity in decimal units, so a 500 GB drive holds 500 billion bytes, but Windows reports sizes in binary units and shows about 465.7 of what it labels GB for the same drive. Early challenges against Western Digital and Seagate were settled, with Western Digital adding disclaimers that usable capacity may differ from the advertised figure.
A 2019 lawsuit was decided in the manufacturers' favor, with the court relying on the decimal definition. For scale, one gigabyte holds roughly an hour of standard-definition video at 2.2 Mbit/s. A single-layer DVD+R holds about 4.7 GB and a single-layer Blu-ray about 25 GB. RAM is still often sized in binary gigabytes, which the IEC would call gibibytes.
1 gigabyte = 1,000,000,000 bytes (exactly).
Sources: Wikipedia: Gigabyte; Wikipedia: Binary prefix; Wikipedia: Gibibyte
Related conversions
- Gigabytes to megabytes (reverse)
- Megabytes to bytes
- Megabytes to kilobytes
- Megabytes to terabytes
- Megabytes to bits
- Megabytes to petabytes
- Megabytes to kibibytes
- Megabytes to mebibytes
- Megabytes to gibibytes
- Megabytes to tebibytes
- Megabytes to kilobits
- Megabytes to megabits
- Megabytes to gigabits
- Bytes to gigabytes
- Kilobytes to gigabytes
- Terabytes to gigabytes
- Bits to gigabytes
- Petabytes to gigabytes
- Kibibytes to gigabytes
- Mebibytes to gigabytes
- Gibibytes to gigabytes
- Tebibytes to gigabytes
- Kilobits to gigabytes
- Megabits to gigabytes
- Gigabits to gigabytes
See all digital storage units.