1 gigabyte equals 1,000 megabytes. Enter a value below to convert instantly.
Gigabytes to megabytes multiplies by 1,000 under the decimal definition used by storage manufacturers, network operators and the SI prefixes themselves. If your file manager reports a different number, it is almost certainly using 1,024 and labelling the result 'GB' anyway.
Need the other direction? Convert megabyte to gigabyte →
Multiply the number of gigabytes by 1000 to get megabytes.
| Gigabytes (GB) | Megabytes (MB) |
|---|---|
| 1 | 1,000 |
| 2 | 2,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 50 | 50,000 |
| 100 | 100,000 |
| 500 | 500,000 |
| 1,000 | 1,000,000 |
A 1 TB drive holds 1,000,000,000,000 bytes, which Windows reports as 931 GB because it is dividing by 1,024 three times and calling the result GB. Nothing is missing; the two numbers use different definitions of the same prefix.
Carriers bill in decimal GB. A 20 GB plan is 20,000 MB, and phone usage counters generally agree because mobile operating systems also use decimal for data accounting.
A 4.7 GB DVD image is 4.7 decimal GB, or about 4.38 GiB. Software that reports the binary figure makes the same file look smaller, which causes confusion when checking whether it will fit.
Memory is genuinely binary — a 16 GB stick is 16 GiB, because memory is addressed in powers of two. Storage is decimal. The same abbreviation means different things in the two contexts, and both are conventional.
Values people actually look up, with the reason each one comes up. Every figure is calculated with the same engine as the converter above.
| Gigabyte (GB) | Megabyte (MB) | What it is |
|---|---|---|
| 0.5 | 500 | A large application |
| 1 | 1,000 | The base conversion |
| 4.7 | 4,700 | A single-layer DVD |
| 8 | 8,000 | A common USB stick |
| 20 | 20,000 | A monthly mobile data plan |
| 64 | 64,000 | A phone's storage |
| 256 | 256,000 | A laptop SSD |
| 1,000 | 1,000,000 | One terabyte |
The SI prefixes are decimal: kilo is 1,000, mega is 1,000,000, giga is 1,000,000,000. Storage manufacturers and networking use them that way. Operating systems historically used powers of 1,024 — 2¹⁰, 2²⁰, 2³⁰ — because memory addressing is binary, but kept the decimal prefix names. IEC 80000-13 resolved the ambiguity in 1998 by introducing kibi, mebi and gibi for the binary values, so 1 GiB = 1,073,741,824 bytes while 1 GB = 1,000,000,000 bytes. Windows still reports GiB values labelled 'GB'; macOS and most Linux distributions switched to decimal GB.
Both definitions are exact within themselves; the imprecision is in the labelling. When a figure matters — a backup that must fit, a quota, a contract — state the unit unambiguously as GB or GiB, or give the byte count. The gap grows with scale: 2.4% at kilo, 4.9% at mega, 7.4% at giga and 10% at tera.
A 1 TB drive really does contain a trillion bytes. The 931 figure is the same capacity divided by 1,024³ and mislabelled.
MB is megabytes; Mb or Mbit is megabits, an eighth as much. Storage is in bytes, network speed is in bits.
Data caps and transfer volumes are decimal. Converting a 20 GB allowance as 20 GiB overstates it by 7.4%.
Content on this page last reviewed 12 August 2026. Spotted an error? Report it — see also how these values are calculated.
1 GB expressed in every other data storage unit on this site.
The gigabyte (GB) is a Metric unit of data storage.
The megabyte (MB) is a Metric unit of data storage.
1,000 MB using the SI decimal prefixes. If your operating system reports 1,024, it is using mebibytes and gibibytes under the older labels.
The drive holds 1,000,000,000,000 bytes. Dividing by 1,024 three times gives 931.32, and the system displays that as 'GB' when it is really GiB. No capacity is missing.
16 GiB — 17,179,869,184 bytes. Memory is addressed in powers of two, so RAM capacities are genuinely binary even though they are labelled GB.
One gigabyte equals 1,000 megabytes.
Multiply the number of gigabytes by 1000 to get megabytes.
One megabyte equals 0.001 gigabytes.
This conversion is common when sizing drives, files, backups, and memory.