A megabyte (MB) and a gigabyte (GB) are units of digital data size, and a gigabyte is the larger of the two: 1 GB equals 1000 MB in the decimal standard, or 1024 MB in the binary standard. The converter below changes any value between bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes entirely in your browser, and lets you pick which standard to use so the numbers line up with either a drive label or what your operating system reports.
What Megabytes and Gigabytes Are
A byte is the basic unit of digital storage, holding a single character of text. Larger amounts of data are named in steps of roughly a thousand: a kilobyte (KB) is about a thousand bytes, a megabyte (MB) is about a thousand kilobytes, and a gigabyte (GB) is about a thousand megabytes. A megabyte holds a small document or a compressed photo, while a gigabyte holds hundreds of photos or several hours of music. Because each step up multiplies by about a thousand, a gigabyte is roughly a thousand times larger than a megabyte.
How to Use It
- Type the number you want to convert into the value field.
- Pick the unit you are converting from, such as MB.
- Pick the unit you want the result in, such as GB.
- Choose the standard: decimal (1000) to match drive labels, or binary (1024) to match what your operating system shows.
- Read the result at the top, with the same value listed across all six units below it.
Decimal (1000) vs Binary (1024)
There are two ways to count storage, and they disagree by a small amount that grows with size. In the decimal standard, each step multiplies by 1000, so 1 GB is 1000 MB. In the binary standard, each step multiplies by 1024, so 1 GB is 1024 MB. Computers work in powers of two, so the binary standard matches how memory and files are actually addressed, while storage makers print the decimal standard because the numbers look bigger and are simpler to multiply.
MB to GB Examples
| Megabytes (MB) | Gigabytes, decimal (1000) | Gigabytes, binary (1024) |
|---|---|---|
| 1 MB | 0.001 GB | 0.000977 GB |
| 100 MB | 0.1 GB | 0.0977 GB |
| 500 MB | 0.5 GB | 0.488 GB |
| 1000 MB | 1 GB | 0.977 GB |
| 1024 MB | 1.024 GB | 1 GB |
| 2048 MB | 2.048 GB | 2 GB |
| 5000 MB | 5 GB | 4.883 GB |
Why the Two Standards Exist
The decimal standard follows the International System of Units (SI), where the prefixes kilo, mega, and giga always mean exactly 1000, 1000000, and 1000000000. The binary standard exists because computer memory is built in powers of two, where 1024 is the natural step rather than 1000. To remove the confusion, the IEC defined separate binary prefixes: a value of 1024 MB counted in binary is properly written as 1 GiB (gibibyte), not 1 GB (gigabyte). In practice most operating systems still display GB while actually counting in GiB, which is the root of the mismatch between a drive label and the capacity your computer reports.
When to Use It
Reach for this converter when a download size, a file, a memory card, or a hosting quota is listed in one unit and you need it in another. Use the decimal standard when you are reading a product spec or a drive label, and the binary standard when you are comparing against the free space your operating system reports. Switching between the two also explains capacity questions, such as why a 64 GB card holds closer to 59 GB of usable space once formatted.
Last Thoughts on Converting MB to GB
Converting megabytes to gigabytes is a single division, but the answer depends on which standard you count in. Divide by 1000 to match the decimal numbers printed on storage products, or divide by 1024 to match the binary numbers your operating system shows. Once you know which standard a number came from, the conversion is exact and the apparent shrinkage of a new drive stops being a mystery.
Keep the converter handy for the next time a file size or a quota is listed in the wrong unit, and explore the rest of our free online tools, including the GB to TB converter, the KB to MB converter, and the bytes to bits converter.
Key Takeaways:
- A gigabyte is larger than a megabyte: 1 GB equals 1000 MB in decimal or 1024 MB in binary.
- To convert MB to GB, divide by 1000 for the decimal standard or by 1024 for the binary standard.
- Storage makers print decimal numbers, while operating systems count in binary, which is why a new drive shows less than its label.
- The SI prefixes kilo, mega, and giga officially mean 1000, while the IEC binary prefixes (KiB, MiB, GiB) mean 1024.
- Use decimal to read product labels and binary to match the free space your computer reports.
- The converter runs entirely in your browser and works across all six units from bytes to petabytes.
Frequently Asked Questions (FAQs)
How many MB are in a GB?
There are 1000 MB in 1 GB using the decimal standard that storage makers use, or 1024 MB in 1 GB using the binary standard that operating systems count in. Both answers are correct; they just rely on different definitions of the gigabyte.
Is 1024 MB equal to 1 GB?
In the binary standard, yes: 1024 MB is exactly 1 GB. In the decimal standard, 1024 MB is 1.024 GB, because a decimal gigabyte is 1000 MB. The converter above shows both so you can match whichever standard your source used.
Why does my new hard drive show less space than advertised?
The label uses the decimal standard, where 1 GB is 1000 MB, but your operating system counts in the binary standard, where 1 GB is 1024 MB. No space is missing; the two systems simply count differently, so the same capacity reads as a smaller number once installed.
What is the difference between GB and GiB?
A gigabyte (GB) officially means 1000000000 bytes under the SI standard, while a gibibyte (GiB) means 1073741824 bytes, which is 1024 to the third power. Many operating systems display GB but actually count in GiB, which causes the mismatch between a drive label and the reported capacity.
How do I convert MB to GB by hand?
Divide the number of megabytes by 1000 for the decimal result, or by 1024 for the binary result. For example, 500 MB is 0.5 GB in decimal or about 0.488 GB in binary. The converter does this instantly and also shows the value in bytes, KB, TB, and PB.
Is this converter free and private?
Yes. The conversion runs entirely in your browser, so no value you enter is sent to a server, logged, or stored anywhere. It is free to use with no sign-up, and it works offline once the page has loaded.
