Convert gigabytes to megabytes instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Gigabytes to megabytes depends on the convention: storage makers use decimal units where 1 GB is 1,000 MB, while operating systems often use binary units where 1 GB is 1,024 MB (technically a gibibyte, GiB). That is why a 500 GB drive shows as about 465 GB in some computers. For file sizes, a 2 GB video is 2,000 MB in decimal terms, or 2,048 MB in binary. Mobile data plans and internet downloads normally use the decimal convention.
How to convert gigabytes to megabytes
Multiply the value by 1024.
MB = GB × 1024Example: 10 GB = 10240 MB.
Gigabytes to Megabytes conversion table
| Gigabytes (GB) | Megabytes (MB) |
|---|---|
| 1 GB | 1024 MB |
| 2 GB | 2048 MB |
| 3 GB | 3072 MB |
| 4 GB | 4096 MB |
| 5 GB | 5120 MB |
| 10 GB | 10240 MB |
| 15 GB | 15360 MB |
| 20 GB | 20480 MB |
| 25 GB | 25600 MB |
| 50 GB | 51200 MB |
| 100 GB | 102400 MB |
Frequently asked questions
How many megabytes is 1 gigabyte?
1 gigabyte equals 1024 megabytes.
What is the formula to convert GB to MB?
To convert GB to MB, multiply the value by 1024. The full formula is: MB = GB × 1024.
How do I convert megabytes back to gigabytes?
Use the same calculator above and type your value into the megabytes field instead — it converts in both directions. Or use the reverse formula: GB = MB ÷ 1024.
Is the GB to MB conversion exact?
The conversion factor used here (1024) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.