Convert gigabytes to megabytes (GB to MB)
To convert gigabytes to megabytes, multiply the value in gigabytes by 1,000. Use it to break storage, data plans or download sizes into megabytes — for example to see how many 5 MB photos fit in your free space. This gb to mb converter works both ways: type gigabytes or megabytes into either box above and the other box, the worked formula and the chart below update as you type.
A gigabyte (GB) is 1,000 megabytes, or one billion bytes. The binary gibibyte (GiB) is 1,073,741,824 bytes — about 7.4% more. Gigabytes are used for phone storage, RAM, mobile data plans, games and video downloads. One gigabyte is 1,000 megabytes.
A megabyte (MB) is 1,000,000 bytes (10⁶) in the SI units used by storage makers and networks. A mebibyte (MiB) is 1,048,576 bytes. Going the other way, one megabyte equals 0.001 gigabytes. Megabytes measure photos (a phone photo is typically a few MB), songs, documents, apps and mobile data use.
How to convert gb to mb with this tool
- Type a number into the Gigabytes (GB) box — it starts at 1 GB as an example.
- Read the answer in the Megabytes (MB) box and in the result panel, which also shows the formula with your number.
- To go the other way, type into the megabytes box, or press the swap button to open the MB to GB converter with your value carried over.
- Choose how many decimal places you want, or tap a quick value such as 0.5 GB, 2 GB, 4 GB.
- Press Copy result to paste the conversion into a message, spreadsheet or note.
GB to MB converter features
Converts both ways
Type in the gigabytes box to get megabytes, or in the megabytes box to get gigabytes. The other box follows instantly.
Exact factor
Calculations use 1 GB = 1,000 MB, and rounding is applied only to the answer you see — choose Auto or 0–10 decimal places.
Formula with your number
The working is shown under the result, for example 1 GB × 1,000 = 1,000 MB, so you can check it or copy the method.
Quick values and chart
Tap common values like 0.5 GB, 2 GB, 4 GB, or read the gigabytes-to-megabytes table further down this page.
Binary units shown
Under the decimal answer you also get the binary one (1 GiB = 1,024 MiB), as used for RAM and by many operating systems.
GB to MB formula
The formula is MB = GB × 1,000. It is exact because SI prefixes step by exactly 1,000: 1 GB = 1,000 MB.
The reverse formula is GB = MB ÷ 1,000 — or use the MB to GB converter. Three worked examples:
- One gigabyte: 1 GB × 1,000 = 1,000 MB
- A 2.5 GB download: 2.5 GB × 1,000 = 2,500 MB
- A 16 GB memory card: 16 GB × 1,000 = 16,000 MB
Decimal (GB) or binary (GiB)?
This converter uses decimal SI prefixes, as drive makers, network speeds and mobile carriers do: each step is × 1,000. Computers often count in powers of two instead — 1 KiB = 1,024 bytes, 1 MiB = 1,024 KiB, 1 GiB = 1,024 MiB and 1 TiB = 1,024 GiB. The IEC introduced these “-bi” names in 1998 so the two systems could be told apart, but Windows still labels binary values “KB”, “MB” and “GB”.
So the same digits can mean two things: 4 GB = 4,000 MB in decimal units, while 4 GiB = 4,096 MiB in binary units. The binary figure is shown under the main answer.
GB to MB quick reference
The values people look up most often, worked out with the exact factor:
- 1 GB = 1,000 MB
- 1 MB = 0.001 GB
- 0.5 GB = 500 MB
- 2 GB = 2,000 MB
- 4 GB = 4,000 MB
- 16 GB = 16,000 MB
Quick tip: Multiply by 1,000 — move the decimal point three places to the right. In binary units, 1 GiB = 1,024 MiB.
Related conversions: GB to TB, KB to MB and the full data storage converter.
GB to MB conversion table
Values in megabytes are rounded to 4 decimal places (more for very small numbers). For any value not listed, type it into the converter above.
| GB | MB | GB | MB |
|---|---|---|---|
| 0.1 | 100 | 8 | 8,000 |
| 0.25 | 250 | 10 | 10,000 |
| 0.5 | 500 | 16 | 16,000 |
| 0.75 | 750 | 20 | 20,000 |
| 1 | 1,000 | 32 | 32,000 |
| 1.5 | 1,500 | 50 | 50,000 |
| 2 | 2,000 | 64 | 64,000 |
| 2.5 | 2,500 | 100 | 100,000 |
| 3 | 3,000 | 128 | 128,000 |
| 4 | 4,000 | 256 | 256,000 |
| 5 | 5,000 | 512 | 512,000 |
GB to MB FAQ
How many megabytes is 4 GB?
4 gigabytes is 4,000 megabytes: 4 GB × 1,000 = 4,000 MB.
How do I convert gb to mb?
Multiply the value in gigabytes by 1,000. For example, 64 GB × 1,000 = 64,000 MB. To convert back, divide the value in megabytes by 1,000 — or use the MB to GB converter.
How many gigabytes are in one megabyte?
One megabyte is 0.001 gigabytes, because 1 MB ÷ 1,000 = 0.001 GB.
What is 64 gigabytes in megabytes?
How many 5 MB photos fit in 16 GB?
16 GB = 16,000 MB, so roughly 16,000 ÷ 5 = 3,200 photos, before allowing for file-system overhead.