Megabyte to Gigabyte
Convert megabyte (MB) to gigabyte (GB) instantly. Compare disk, RAM and download sizes.
Megabyte → Gigabyte
0.000977
GB
1 MB = 0.000977 GB
Frequently asked questions
Both answers are in use. The decimal SI definition makes 1 GB equal 1,000 MB, and it is used by storage manufacturers, network operators and by macOS and Linux. The binary definition makes 1 GiB equal 1,024 MiB, and it is used by Windows and for RAM. The difference is 2.4% at this scale and grows as you move up the units.
Roughly 0.7 GB per hour for standard definition, about 3 GB per hour for 1080p and around 7 GB per hour for 4K. A 1.5 GB daily mobile plan is therefore about two hours of SD video, or half an hour of HD, before anything else is counted.
The capitalisation carries the whole meaning. MB is megabytes, a measure of data. Mb or Mbps is megabits, a measure of rate used for connection speeds. There are 8 bits in a byte, so a 100 Mbps connection transfers at most 12.5 MB per second — a factor-of-eight difference that ISPs benefit from, since megabits produce the larger number.
A thousand, or a thousand and twenty-four
Converting megabytes to gigabytes has two defensible answers, and which one applies depends on who is doing the counting.
Decimal (SI): 1 GB = 1,000 MB. Used by storage manufacturers, network operators and increasingly by operating systems.
Binary: 1 GiB = 1,024 MiB. Used historically by Windows, by RAM specifications, and by much software.
The difference at this scale is 2.4%, which sounds trivial and compounds as you move up the units.
Why two systems exist
Computers address memory in powers of two, so 2¹⁰ = 1,024 was a natural grouping and early practice borrowed the SI prefix "kilo" for it despite the mismatch. As capacities grew, the discrepancy between the borrowed prefix and its actual SI meaning became significant.
The IEC resolved this in 1998 by defining distinct binary prefixes — kibi (KiB), mebi (MiB), gibi (GiB), tebi (TiB) — leaving kilo, mega and giga with their proper decimal meanings. Adoption has been partial: Linux and macOS report decimal GB, Windows still reports binary values while labelling them "GB", and RAM is universally specified in binary regardless of label.
Where this matters in practice
Mobile data plans. Indian operators sell data in decimal GB — a "1.5 GB per day" plan means 1,500 MB. Your phone may report usage in binary, so the two counters can disagree slightly.
App and file sizes. An app listed as 150 MB on a store page is decimal; the storage it consumes on a Windows machine will be reported using binary division and appear slightly smaller.
Cloud storage quotas, which are decimal at all major providers.
Video streaming. Rough consumption rates: standard definition around 0.7 GB per hour, 1080p around 3 GB per hour, and 4K around 7 GB per hour. A 1.5 GB daily plan is therefore about two hours of SD or half an hour of HD.
Common values
Decimal:
- 100 MB = 0.1 GB
- 500 MB = 0.5 GB
- 1,000 MB = 1 GB
- 1,500 MB = 1.5 GB
- 5,000 MB = 5 GB
Binary:
- 1,024 MiB = 1 GiB
- 2,048 MiB = 2 GiB
- 5,120 MiB = 5 GiB
Megabits are not megabytes
The other common confusion, and it costs a factor of eight.
MB is megabytes — a measure of data. Mb or Mbps is megabits — a measure of rate, used for connection speeds.
There are 8 bits in a byte, so a 100 Mbps connection transfers at most 12.5 MB per second. Downloading a 1 GB file on that connection takes about 80 seconds at best, not 10.
The capitalisation carries the whole meaning, which is why it is so frequently mistaken. ISPs advertise in megabits because the number is larger.