How do you convert GB to MB?
Multiply by 1,000 for decimal gigabytes. If the size came from a program that counts in binary, multiply by 1,024 instead: 4 GB is then 4,096 MB rather than 4,000 MB.
- 1 GB (decimal)
- 1,000 MB
- 1 GB (binary)
- 1,024 MB
- 1 MB
- 0.001 GB
GB to MB table
| 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 |
| Gigabytes (GB) | Megabytes (MB) |
|---|---|
| 12 | 12,000 |
| 15 | 15,000 |
| 20 | 20,000 |
| 25 | 25,000 |
| 30 | 30,000 |
| 40 | 40,000 |
| 50 | 50,000 |
| 60 | 60,000 |
| 75 | 75,000 |
| 100 | 100,000 |
Two meanings of the same letters
The gap grows with every prefix. At the megabyte level the binary unit is about 4.9% larger, and at the gigabyte level about 7.4%. That is why a drive sold as 500 GB shows up as roughly 465 GB in Windows: the bytes are all there, they are just divided by a bigger number.
When you plan an upload or an email attachment, use whatever unit the receiving service quotes. If a form asks for a file under 2 MB and your file manager counts in binary, a file shown as 1.95 MB is about 2.04 million bytes and can still be rejected.
Shrinking a file to a megabyte limit
Converting the number is often the easy part; the file itself is too big. Compress video and compress PDF cut large files down to a target size, and the MB to GB converter runs this conversion the other way.
GB to MB questions
How many MB are in 1 GB?
1,000 MB in the decimal system used by drive makers, phone sellers and macOS. In the binary reading used by Windows and many older programs, 1 GB is 1,024 MB.
How many megabytes is 2.5 GB?
2,500 MB in decimal units, or 2,560 MB if you count in binary steps of 1,024.
Why does my 128 GB phone show less free space?
Part of the storage holds the operating system and preinstalled apps. On top of that, a device that counts in binary shows 128 billion bytes as about 119 GB, even though nothing is missing.
Is a gigabyte of mobile data 1,000 or 1,024 MB?
Carriers set their own rules for metering, so check the plan terms. Many count in decimal units, but some round each session or bill in binary steps.
From the blog
Social & Mobile · 10 min read
Why Phone Videos Are So Big, and How to Compress One Sensibly
Resolution, frame rate, HDR and codec decide how big a phone video gets. Here is what each setting costs and the order that shrinks a clip with the least visible loss.
File Formats & Fixes · 11 min read
How to Unzip a File, and What Each ZIP Error Message Means
Unzip any ZIP on a computer or phone in a minute, then match the error you see, from damaged archives and passwords to split parts and garbled names, to its fix.
