Megabytes to Gigabytes
One gigabyte is one thousand megabytes in the decimal SI system, so you divide megabytes by 1,000 to get gigabytes: 500 MB is 0.5 GB and 2,500 MB is 2.5 GB. If your software counts in binary units, divide by 1,024 instead.
1 megabyte = 0.001 gigabytes
1 MB = 0.001 GB · multiply by 0.001
Two kinds of gigabyte
Storage makers, network providers and the SI system use decimal prefixes, so 1 GB is 1,000 MB and 1,000,000,000 bytes. Computers address memory in powers of two, so programmers long used the same letters for 1,024-based units. In 1998 the IEC introduced separate names to end the clash: a mebibyte (MiB) is 1,048,576 bytes and a gibibyte (GiB) is 1,024 MiB, or 1,073,741,824 bytes.
Windows still labels binary sizes as KB, MB and GB, while macOS has used decimal units since 2009 and many Linux tools print MiB and GiB explicitly. That is why the same 4,700 MB file shows as 4.7 GB on a Mac and about 4.38 GB in Windows. Neither is wrong; they are counting in different steps.
Megabytes on a phone data plan
Mobile carriers sell data in gigabytes and apps report usage in megabytes, so this conversion is how you check whether you will last the month. Streaming services publish rough figures: Netflix estimates about 1 GB per hour in standard definition and up to 3 GB per hour in HD, so a 90-minute HD film can use more than 4,000 MB. A video call often runs a few hundred megabytes per hour, and music at high quality around 100–150 MB per hour.
Carriers count usage in their own way and round each session, so treat the converter as a guide rather than an audit. Sending video eats data fast; shrinking a clip with compress video to 10 MB before you share it saves both upload time and plan allowance.
Megabytes to gigabytes at a glance
Seven values you meet most often. The tables and the converter handle everything in between.
- 1 MB0.001 GB
- 2 MB0.002 GB
- 5 MB0.005 GB
- 10 MB0.01 GB
- 20 MB0.02 GB
- 50 MB0.05 GB
- 100 MB0.1 GB
Megabytes to gigabytes conversion table
Rounded to six significant digits. Change any value in the converter above for an exact figure.
| Megabytes (MB) | Gigabytes (GB) |
|---|---|
| 1 | 0.001 |
| 2 | 0.002 |
| 3 | 0.003 |
| 4 | 0.004 |
| 5 | 0.005 |
| 6 | 0.006 |
| 7 | 0.007 |
| 8 | 0.008 |
| 9 | 0.009 |
| 10 | 0.01 |
| 12 | 0.012 |
| 15 | 0.015 |
| 20 | 0.02 |
| 25 | 0.025 |
| 30 | 0.03 |
| 40 | 0.04 |
| 50 | 0.05 |
| 60 | 0.06 |
| 70 | 0.07 |
| 75 | 0.075 |
| 80 | 0.08 |
| 90 | 0.09 |
| 100 | 0.1 |
| Gigabytes (GB) | Megabytes (MB) |
|---|---|
| 1 | 1,000 |
| 2 | 2,000 |
| 3 | 3,000 |
| 4 | 4,000 |
| 5 | 5,000 |
| 6 | 6,000 |
| 7 | 7,000 |
| 8 | 8,000 |
| 9 | 9,000 |
| 10 | 10,000 |
| 12 | 12,000 |
| 15 | 15,000 |
| 20 | 20,000 |
| 25 | 25,000 |
| 30 | 30,000 |
| 40 | 40,000 |
| 50 | 50,000 |
| 60 | 60,000 |
| 70 | 70,000 |
| 75 | 75,000 |
| 80 | 80,000 |
| 90 | 90,000 |
| 100 | 100,000 |
Quick checks
Move the decimal point three places to the left: 750 MB is 0.75 GB, 12,000 MB is 12 GB. If the answer must match a Windows dialog, divide by 1,024 instead: 12,000 MiB is 11.72 GiB. The opposite direction, with storage examples, is on the GB to MB page, and the unit converter covers bits, kilobytes and terabytes too.
Frequently asked questions
- Is 1 GB 1,000 MB or 1,024 MB?
- In SI and on drive packaging, 1 GB is 1,000 MB. Windows and some older software use GB to mean 1,024 MB, which is properly called a gibibyte (GiB).
- How many GB is 1,500 MB?
- 1.5 GB in decimal units, or 1.46 GiB if you divide by 1,024.
- How much mobile data does an hour of HD streaming use?
- Usually between 1.5 and 3 GB, which is 1,500 to 3,000 MB, depending on the service and the resolution it picks.
- Why does my 4.7 GB file look smaller in Windows?
- Windows divides by 1,024 at each step, so 4.7 billion bytes appear as about 4.38 GB. The file is the same size; only the unit differs.