Convert digital storage capacity across decimal and binary units in real time. Whether you need to convert Gigabytes (GB) to Megabytes (MB), or calculate binary equivalents like Mebibytes (MiB) and Gibibytes (GiB), this free online tool delivers accurate results instantly.
Why Data Storage Units Differ: Decimal vs. Binary
A common source of confusion when managing digital storage is the difference between how storage manufacturers measure capacity and how computer operating systems display it.
Decimal Standard (SI Units – Base 10)
International System of Units (SI) standards use base-10 calculations. In base 10, prefixes increase by powers of 1,000.
- 1 Kilobyte (KB) = 1,000 Bytes
- 1 Megabyte (MB) = 1,000,000 Bytes (1,000 KB)
- 1 Gigabyte (GB) = 1,000,000,000 Bytes (1,000 MB)
- 1 Terabyte (TB) = 1,000,000,000,000 Bytes (1,000 GB)
Hard drive, SSD, and flash drive manufacturers label storage capacity using the base-10 decimal system.
Binary Standard (IEC Units – Base 2)
Computers process data in binary (0s and 1s), so operating systems naturally operate on base-2 mathematics where prefixes increase by powers of 1,024 (210). The International Electrotechnical Commission (IEC) established specific binary terms to prevent confusion:
- 1 Kibibyte (KiB) = 1,024 Bytes
- 1 Mebibyte (MiB) = 1,048,576 Bytes (1,024 KiB)
- 1 Gibibyte (GiB) = 1,073,741,824 Bytes (1,024 MiB)
- 1 Tebibyte (TiB) = 1,099,511,627,776 Bytes (1,024 GiB)
Operating systems like Microsoft Windows calculate file sizes using base-2 values (1024), but often label them using SI abbreviations (GB, MB). This is why a brand-new 1 TB external hard drive shows up as approximately 931 GB in Windows Explorer.
Data Storage Conversion Reference Table
| Storage Unit | Symbol | Standard Equivalent (Base 10) | Binary Equivalent (Base 2) |
|---|---|---|---|
| Bit | b | Single binary digit (0 or 1) | Single binary digit (0 or 1) |
| Byte | B | 8 Bits | 8 Bits |
| Kilobyte / Kibibyte | KB / KiB | 1,000 Bytes | 1,024 Bytes |
| Megabyte / Mebibyte | MB / MiB | 1,000 KB (1,000,000 B) | 1,024 KiB (1,048,576 B) |
| Gigabyte / Gibibyte | GB / GiB | 1,000 MB | 1,024 MiB |
| Terabyte / Tebibyte | TB / TiB | 1,000 GB | 1,024 GiB |
| Petabyte / Pebibyte | PB / PiB | 1,000 TB | 1,024 TiB |
How to Use the Data Storage Converter
Converting digital storage values takes just a few clicks:
- Select the Source Unit: Choose the unit you want to convert from using the From dropdown menu (e.g., Megabyte or Gigabyte).
- Select the Target Unit: Choose the unit you want to convert into using the To dropdown menu (e.g., Mebibyte or Terabyte).
- Enter the Value: Type the numeric quantity into the Value to Convert field.
- Calculate: Click the blue Calculate button to instantly generate your exact conversion in the Answer box.
- Swap or Reset: Use the green swap button between the dropdowns to reverse the conversion direction, or press Clear to start a new calculation.
If you are measuring network file transfers, internet bandwidth, or streaming performance, try our Data Transfer Rate Converter to switch between Mbps, MB/s, and Gbps.
Frequently Asked Questions (FAQs)
1. Why does my 1 TB hard drive show up as 931 GB on Windows?
Hard drive manufacturers define 1 Terabyte (TB) using the base-10 decimal system (1 TB = 1,000,000,000,000 bytes). Windows calculates storage capacity using the base-2 binary system (1 GiB = 1,073,741,824 bytes). When Windows divides 1,000,000,000,000 by 1,073,741,824, the result is roughly 931.32 GiB (which Windows mislabels as GB).
2. What is the difference between MB and MiB?
A Megabyte (MB) is a base-10 unit equal to 1,000,000 bytes (1,000 kilobytes). A Mebibyte (MiB) is a base-2 binary unit equal to 1,048,576 bytes (1,024 kibibytes). A Mebibyte is about 4.86% larger than a Megabyte.
3. How many Megabytes (MB) are in a Gigabyte (GB)?
In the standard SI decimal system, there are exactly 1,000 Megabytes in 1 Gigabyte. In binary notation (GiB to MiB), 1 Gibibyte contains 1,024 Mebibytes.
4. What is the difference between a Bit and a Byte?
A bit (lowercase “b”) is the smallest unit of digital data, representing a single binary value of 0 or 1. A Byte (uppercase “B”) consists of 8 bits grouped together. Bytes measure storage capacity (e.g., GB), while bits measure data transmission speeds (e.g., Mbps).
5. Which is bigger: a Terabyte (TB) or a Petabyte (PB)?
A Petabyte (PB) is significantly larger than a Terabyte (TB). One Petabyte equals 1,000 Terabytes (or 1,024 Tebibytes in the binary system).
6. Why do internet service providers measure speed in bits while file sizes use Bytes?
Internet Service Providers (ISPs) measure network performance in bits per second (e.g., Megabits per second, or Mbps) because network protocols transmit data sequentially one bit at a time. Storage systems group bits into 8-bit Bytes to store complete characters or code, so file sizes are measured in Bytes (e.g., MB or GB).
7. Is a Kibibyte (KiB) larger than a Kilobyte (KB)?
Yes. A Kibibyte (KiB) equals 1,024 bytes, whereas a standard Kilobyte (KB) equals 1,000 bytes. A Kibibyte is 24 bytes larger than a Kilobyte.
8. What is the largest standardized unit of data storage?
The largest official SI prefix for data storage is the Quettabyte (QB), introduced in 2022 by the International Bureau of Weights and Measures. One Quettabyte equals 1030 bytes (1,000,000,000,000,000,000,000,000,000,000 bytes), succeeding the Yottabyte (1024 bytes).