MB to GB converter
Type an amount in megabytes and see at once how many gigabytes that is. You can also convert from GB to MB. Choose whether to use 1000 or 1024: that difference explains why a drive seems to have less space than the box says.
In megabytes or in gigabytes, depending on your choice.
Fill in the fields; the answer appears here straight away.
How it's worked out
How it works
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Enter the values
Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.
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Instant answer
The answer appears as you type, with the most important intermediate values.
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See the working
Under "How it's worked out" you see the steps, handy for checking your own calculation.
1000 or 1024?
- Decimal (1000): 1 GB = 1000 MB. This is how makers of drives, SSDs and memory cards count, and macOS too.
- Binary (1024): 1 GB = 1024 MB. This is how Windows counts, and it also calls it "GB". The official name is gibibyte (GiB).
A 500 GB drive (decimal) therefore shows up as about 465 GB in Windows: 500 × 1000³ ÷ 1024³ = 465.7.
Example
2500 MB is 2500 ÷ 1000 = 2.5 GB (decimal) or 2500 ÷ 1024 = 2.44 GB (binary).
Conversion table (decimal)
| MB | GB |
|---|---|
| 1 MB | 0.001 GB |
| 100 MB | 0.1 GB |
| 256 MB | 0.256 GB |
| 500 MB | 0.5 GB |
| 512 MB | 0.512 GB |
| 1,000 MB | 1 GB |
| 1,024 MB | 1.024 GB |
| 2,500 MB | 2.5 GB |
| 5,000 MB | 5 GB |
| 10,000 MB | 10 GB |
Everyday sizes
| Item | MB | GB (decimal) |
|---|---|---|
| Phone photo (about) | 3 | 0.003 |
| A DVD | 4,700 | 4.7 |
| 1,000 photos of 3 MB | 3,000 | 3 |
| A five-minute song (about) | 5 | 0.005 |
A memory card of 128 GB shows up as 119.2 GB on a computer that counts in 1024, because 128 × 10⁹ ÷ 2³⁰ ≈ 119.2.
Checking a text size
Text takes far less space than media: a plain-text page is only a few kilobytes. To count the characters in a text before it goes into a database field, use the character counter. And for a number system with powers of two, see the number base converter.
Frequently asked questions
Why does my 500 GB drive show about 465 GB?
The maker counts 1 GB as 1,000,000,000 bytes, while Windows divides by 1,073,741,824. 500 × 10⁹ ÷ 2³⁰ ≈ 465.7. No space is missing; the same bytes are written in a different unit.
What are MiB and GiB?
Mebibyte and gibibyte are the binary units: 1 MiB = 1,048,576 bytes and 1 GiB = 1,073,741,824 bytes. Windows shows them as MB and GB. Use the 1024 option to convert with them.
Which should I use, 1000 or 1024?
Use 1000 for storage sizes, mobile data and network speeds. Use 1024 for RAM, and when matching what Windows reports for files and drives.
How many MB is a 20 GB data plan?
20,000 MB by the decimal rule, or 20,480 MB by the binary rule. Mobile operators count in decimal, so the plan holds 20,000 MB.