Gigabytes (GB) to Megabytes (MB) Converter
Enter your Gigabytes (GB) value to convert to Megabytes (MB). 1 GB = 1,000 MB, calculated across both decimal (SI) and binary (IEC) standards.
Convert Gigabytes to Megabytes
Do you want to convert megabytes to gigabytes?
How to Convert Gigabytes to Megabytes
To convert gigabytes to megabytes, multiply by 1,000 (using SI decimal). Both units measure storage capacity—the difference is scale. Try the calculate MB to GB.
GB: A gigabyte is 1,000 megabytes or 1,000,000,000 bytes using the SI decimal standard. This is what hard drive manufacturers typically use. See also: how many Kilobytes in a GB.
MB: A megabyte is 1,000 kilobytes or 1,000,000 bytes using the SI decimal standard. See also: how many MB in Zebibits.
1 GB = 1,000 MB (using SI decimal standard) — which means there are 1,000megabytes in every gigabyte.
GB to MB Conversion Formula
// Convert GB to MB
MB = GB × 1,000
// Reverse: Convert MB to GB
GB = MB × 0.001
GB to MB Conversion Examples
100 GB = 100,000 MB
256 GB = 256,000 MB
500 GB = 500,000 MB
1,000 GB = 1,000,000 MB
2,048 GB = 2,048,000 MB
Binary Standard (Base 1024)
Using binary calculation: 1 GB = 1,024 MB
100 GB = 102,400 MB
1,000 GB = 1,024,000 MB
1,024 GB = 1,048,576 MB
What Is a Gigabyte?
A gigabyte is 1,000 megabytes or 1,000,000,000 bytes using the SI decimal standard. This is what hard drive manufacturers typically use. Related: Petabits to Mb.
The gigabyte is a SI decimal unit of digital information storage. It uses base 1,000 following the SI (International System of Units) standard. Try the convert Pbps to Petabytes Per Second.
Common uses: Movies, video games, smartphone storage, USB drives, cloud storage plans You might also need: Gigabytes to Kb calculator.
1 GB = 8 × 10⁹ bits = 1 × 10⁹ bytes.
The gigabyte can be abbreviated as GB; for example, 1 gigabyte can be written as 1 GB.
What Is a Megabyte?
A megabyte is 1,000 kilobytes or 1,000,000 bytes using the SI decimal standard. Try the ZiB to Megabytes converter.
The megabyte is a SI decimal unit of digital information storage. It uses base 1,000 following the SI (International System of Units) standard. You might also need: Exbibits to Tebibits conversion.
Common uses: MP3 files, high-resolution images, short video clips, software installers Check out our convert Gibibytes Per Second to Tebibits Per Second.
1 MB = 8 × 10⁶ bits = 1 × 10⁶ bytes.
The megabyte can be abbreviated as MB; for example, 1 megabyte can be written as 1 MB.
Gigabyte to Megabyte Conversion Table
The table below shows various gigabyte measurements converted to megabytes.
| Gigabytes | Megabytes | Megabytes (Binary) |
|---|---|---|
| 1 GB | 1,000 MB | 1,024 MB |
| 2 GB | 2,000 MB | 2,048 MB |
| 5 GB | 5,000 MB | 5,120 MB |
| 10 GB | 10,000 MB | 10,240 MB |
| 25 GB | 25,000 MB | 25,600 MB |
| 50 GB | 50,000 MB | 51,200 MB |
| 100 GB | 100,000 MB | 102,400 MB |
| 128 GB | 128,000 MB | 131,072 MB |
| 250 GB | 250,000 MB | 256,000 MB |
| 256 GB | 256,000 MB | 262,144 MB |
| 500 GB | 500,000 MB | 512,000 MB |
| 512 GB | 512,000 MB | 524,288 MB |
| 1,000 GB | 1,000,000 MB | 1,024,000 MB |
| 1,024 GB | 1,024,000 MB | 1,048,576 MB |
SI Decimal vs Binary: Why Two Different Standards?
When converting gigabytes to megabytes, different tools may give slightly different results. This is because there are two competing standards for measuring digital storage:
| Standard | Base | 1 KB equals | Used By |
|---|---|---|---|
| SI Decimal | 1000 | 1,000 bytes | Hard drive manufacturers, macOS, network speeds |
| Binary (IEC) | 1024 | 1,024 bytes | Windows, Linux (partially), RAM specifications |
Why Does My Hard Drive Show Less Space Than Advertised?
This difference in standards explains the common "missing hard drive space" confusion.
Example: A "500 GB" Hard Drive
- Contains exactly: 500,000,000,000 bytes
- macOS (SI Decimal): Displays 500 GB (divides by 1,000³)
- Windows (Binary): Displays 465 GB (divides by 1,024³)
The Verdict: Same bytes, same drive—just different math. No space is actually missing.
Note: Our calculator defaults to SI decimal (base 1000) to match the box label. To match Windows, toggle the standard at the top of the calculator.
💡 Storage Engineer Tip
Manufacturers label drives using SI decimal (base 1000). Windows divides by 1024 instead—that's why a "1 TB" drive shows as 931 GB. Same bytes, different math.
— Subash Geetha Krishnan, 15+ years in enterprise storage
When to Convert GB to MB
Common scenario: Breaking down a game or app download into individual file sizes, or verifying backup job sizes. Learn more: Gigabytes to Mebibits calculator.
Other situations include storage planning for calculating how much data fits in a given capacity, file management for understanding sizes across different scales, cost estimation for budgeting cloud storage, and backup planning for determining media requirements. Learn more: PiB to MB conversion rate.