MB to GB Converter
500 MB converts to exactly 0.5 GB under the decimal standard, or about 0.4883 GB under the binary standard your computer actually uses internally. This MB to GB converter switches between megabytes and gigabytes in both directions, and lets you pick which math to use. Decimal math (divide or multiply by 1000) is what hard drive and SSD manufacturers print on the box. Binary math (divide or multiply by 1024) is what Windows, macOS, and most file managers use when they calculate the number they display next to a file, even though the on-screen label still reads "MB" or "GB." Enter a value, choose a direction, and pick a standard to get an instant, accurate result.
Quick answer
A gigabyte equals 1000 megabytes under the decimal standard, the convention drive makers and cloud storage providers use.
1 GB = 1000 MB (drive & data plan labels)
Converted Value
0.5 GB
Standard applied
Decimal (1 GB = 1000 MB)
Conversion factor
1000
What this tells you
- •A gigabyte equals 1000 megabytes under the decimal standard, the convention drive makers and cloud storage providers use.
- •A gigabyte equals 1024 megabytes under the binary standard, the convention your operating system's file explorer uses internally.
- •The two standards produce different answers for the same input, and the gap grows as the numbers get larger.
- •This converter defaults to decimal because that matches most product listings and data plan documents, but you can switch to binary in one click when you need to match what your OS reports.
How to Use
- 1Type the number you want to convert into the Value field.
- 2Pick a direction: MB to GB or GB to MB.
- 3Pick a standard: Decimal (1000) or Binary (1024), depending on whether you want vendor-style math or OS-style math.
- 4Read the converted value immediately below the inputs, along with the exact conversion factor that was applied.
How It Works
Formula
Decimal: GB = MB / 1000, MB = GB x 1000
Binary: GB = MB / 1024, MB = GB x 1024Megabytes and gigabytes are both units of digital storage, and a gigabyte is always a fixed multiple of a megabyte. The question is which multiple. The decimal standard treats 1 GB as 1000 MB, matching the metric prefix "giga" and matching how storage vendors label drives and how cloud providers meter data plans. The binary standard treats 1 GB as 1024 MB, because computers naturally count storage in powers of two, and this is the math your operating system runs when it reports a file or folder size, even while displaying the label "MB" or "GB" instead of the technically correct "MiB" or "GiB." This converter applies whichever factor you select and divides or multiplies accordingly.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Converting a 500 MB download to GB
500 divided by 1000 equals 0.5. This is the figure you would see quoted on a product page or in a mobile data plan that measures usage in decimal gigabytes.
The same 500 MB file, measured the way your OS measures it
500 divided by 1024 equals about 0.4883. File explorers on Windows and macOS use this binary math internally, which is why a file listed as 500 MB in one context can appear as a slightly different GB figure elsewhere.
Converting 2 GB of storage into MB
2 multiplied by 1000 equals 2000. This matches how a 2 GB data allowance or a 2 GB file size is normally advertised.
1 GB of RAM expressed in MB
1 multiplied by 1024 equals 1024. Memory (RAM) capacity is almost always a binary quantity, so 1 GB of RAM is 1024 MB of RAM, not 1000.
MB to GB quick reference
Common megabyte values converted to gigabytes under both standards.
| MB | GB (decimal, /1000) | GB (binary, /1024) |
|---|---|---|
| 1 | 0.001 | 0.000977 |
| 10 | 0.01 | 0.009766 |
| 100 | 0.1 | 0.097656 |
| 500 | 0.5 | 0.488281 |
| 1000 | 1 | 0.976563 |
| 5000 | 5 | 4.882813 |
| 10000 | 10 | 9.765625 |
Binary values are rounded to six decimal places. Use the converter above for a value not listed here.
Why does a 500 GB drive show less than 500 GB in Windows?
This is one of the most common questions people have after buying storage, and the short answer is that nothing is missing. Drive manufacturers label capacity using the decimal standard, where 1 GB equals exactly 1,000,000,000 bytes. That is the definition set by the International System of Units, and it is the one printed on the box.
Windows, however, calculates the number it shows you in File Explorer using the binary standard, where 1 GB (technically a GiB) equals 1,073,741,824 bytes. Take a drive advertised as 500 GB, convert its 500,000,000,000 bytes using the binary factor instead of the decimal one, and you land on roughly 465.66, which Windows rounds and labels "GB" on screen.
macOS switched its Finder to decimal reporting some years ago, so a Mac will usually show a number much closer to the advertised capacity. Windows still reports in binary, which is why the gap tends to show up more often on PCs. A small additional amount of space is also reserved for the file system and partition structure, but that accounts for only a sliver of the difference. The standard mismatch is the main cause, and it is a labeling difference, not a defect or a sign of counterfeit storage.
Common mistakes
- Assuming MB to GB conversion always means dividing by 1000. Operating systems and RAM specs use 1024, so the same input can produce two different, both-correct answers depending on context.
- Comparing a drive's advertised capacity directly to what the OS reports without accounting for the standard. A drive is not missing storage just because the two numbers do not match.
- Using binary math for a mobile data plan or cloud storage quota. Carriers and cloud providers almost always bill in decimal gigabytes, so binary math will make your remaining balance look smaller than it really is.
- Rounding too early in a multi-step conversion. Round only the final displayed value, not an intermediate result you plan to convert again.
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