Data Storage Converter
Digital storage converter for files and drives — bits up to terabytes.
Convert between bits, bytes, kilobytes, megabytes, gigabytes and terabytes. This converter uses the binary convention (1 KB = 1,024 bytes), the way most operating systems report file sizes. The page explains how that differs from drive-maker "decimal" sizes.
Popular Data Storage Conversions
- Gigabyte to Megabyte
- Megabyte to Gigabyte
- Terabyte to Gigabyte
- Gigabyte to Terabyte
- Megabyte to Kilobyte
- Kilobyte to Byte
- Byte to Bit
- Bit to Byte
- Gigabyte to Kilobyte
All Data Storage Units
| Unit | Symbol | Definition |
|---|---|---|
| Bit | bit | The smallest unit of digital information, a single binary 0 or 1. |
| Byte | B | Equal to 8 bits, commonly representing a single character. |
| Kilobyte | KB | Equal to 1,024 bytes in the binary convention used by most operating systems. |
| Megabyte | MB | Equal to 1,024 kilobytes. |
| Gigabyte | GB | Equal to 1,024 megabytes (2^30 bytes, the binary convention; drive makers use 10^9 bytes, formally written GiB for the binary value). |
| Terabyte | TB | Equal to 1,024 gigabytes (2^40 bytes, binary convention; drive makers use 10^12 bytes, so a 1 TB drive shows about 931 GB). |
How data-storage conversion works
A bit is a single 0 or 1. A byte is 8 bits. Larger units multiply by 1,024 (2¹⁰) in the binary convention used here:
1 KB = 1,024 bytes
1 MB = 1,024 KB = 1,048,576 bytes
1 GB = 1,024 MB = 1,073,741,824 bytes
1 TB = 1,024 GB = 1,099,511,627,776 bytes
GB to MB: multiply by 1,024. MB to GB: divide by 1,024. Bytes to bits: multiply by 8.
Decimal (SI) vs binary: why your drive shows less space
There are two conventions. Storage manufacturers use the decimal (SI) meaning: 1 GB = 1,000,000,000 bytes and 1 TB = 10¹² bytes. Many operating systems count in binary but still label the result "GB". The International Electrotechnical Commission created the names KiB, MiB, GiB and TiB (kibibyte, mebibyte, gibibyte, tebibyte) for the binary values so that the two can be told apart.
| Advertised (decimal) | Bytes | Shown as (binary) |
|---|---|---|
| 500 GB drive | 500,000,000,000 bytes | 465.66 GB (binary) |
| 1 TB drive | 1,000,000,000,000 bytes | 931.32 GB (binary) |
| 2 TB drive | 2,000,000,000,000 bytes | 1862.65 GB (binary) |
| 128 GB phone | 128,000,000,000 bytes | 119.21 GB (binary) |
| 256 GB phone | 256,000,000,000 bytes | 238.42 GB (binary) |
A "1 TB" drive therefore shows about 931 GB. Nothing is missing, because 10¹² ÷ 2³⁰ ≈ 931.3. Part of the space is also used by the file system and the operating system, so real free space is a little lower.
Internet speed: Mbps vs MB/s, and download time
Connection speeds are advertised in megabits per second (Mbps) while downloads are shown in megabytes per second (MB/s). Divide Mbps by 8 to get MB/s.
| Connection | Speed in MB/s | Time for 1 GB |
|---|---|---|
| 10 Mbps | 1.25 MB/s | 14.3 min |
| 20 Mbps | 2.5 MB/s | 7.2 min |
| 50 Mbps | 6.25 MB/s | 2.9 min |
| 100 Mbps | 12.5 MB/s | 1.4 min |
| 200 Mbps | 25 MB/s | 0.7 min |
Real downloads are slower because of network overhead, shared bandwidth and server limits.
Where each unit is used
- Bits: network speeds and encryption key lengths.
- Bytes and KB: text files, emails and small documents.
- MB: photos, songs, PDFs and mobile app data usage.
- GB: videos, games, phone storage and RAM, and mobile data packages.
- TB: hard drives, cloud backups and servers.
Common mistakes to avoid
- Bit vs byte. A lowercase "b" is bits and an uppercase "B" is bytes. 100 Mbps is only 12.5 MB/s.
- Assuming 1 GB is always 1,000 MB. It is 1,000 MB in decimal (drive makers, network data plans) and 1,024 MB in binary (many operating systems). Check which one a plan or tool uses.
- Forgetting overhead. Formatting, file systems and system files take space on every drive.
Exact conversion factors
| Unit | Symbol | Exact factor |
|---|---|---|
| Bit | bit | 1 bit = 0.125 B |
| Byte | B | 1 B = 1 B |
| Kilobyte | KB | 1 KB = 1024 B |
| Megabyte | MB | 1 MB = 1048576 B |
| Gigabyte | GB | 1 GB = 1073741824 B |
| Terabyte | TB | 1 TB = 1099511627776 B |
Sources: IEC 80000-13 and IEC 60027-2 (binary prefixes KiB, MiB, GiB); NIST guidance on prefixes for binary multiples.
Frequently Asked Questions
How many MB are in a GB?
In the binary convention used by this converter, 1 GB = 1,024 MB. In decimal (SI) units used by drive makers, 1 GB = 1,000 MB.
How many bytes are in a GB?
1 GB is 1,073,741,824 bytes in binary units (strictly a gibibyte, GiB) or 1,000,000,000 bytes in decimal.
How many bits are in a byte?
A byte has 8 bits.
Why does my 1 TB drive show about 931 GB?
The manufacturer counts 1 TB as 1,000,000,000,000 bytes, while the system divides by 2³⁰ and labels the result GB. 10¹² ÷ 1,073,741,824 ≈ 931.3.
How do I convert Mbps to MB/s?
Divide megabits per second by 8. For example, 100 Mbps = 12.5 MB/s.
How many KB are in a MB?
1 MB equals 1,024 KB in binary units, and 1,000 KB in decimal units.
What is the difference between GB and GiB?
GB (gigabyte) strictly means 10⁹ bytes. GiB (gibibyte) means 2³⁰ = 1,073,741,824 bytes. Many systems use "GB" for the binary value.
All Data Storage Conversions
Choose a starting unit to see every conversion available from it.