What this data storage converter does
Computer storage is sold and reported in bytes, kilobytes, megabytes, gigabytes and terabytes, but the way those prefixes are counted is a common source of confusion. This converter uses the binary convention in which each step up is a factor of 1,024: 1 KB is 1,024 bytes, 1 MB is 1,024 KB, and so on. This is the way operating systems such as Windows traditionally report file sizes and memory, and strictly speaking the units are called kibibytes, mebibytes, gibibytes and tebibytes.
Use it when you need to know how many megabytes fit in a gigabyte of RAM, how big a set of files will be in another unit, or how many photos fit on a drive. Pick the starting unit, the target unit, and the value. The calculator converts everything to bytes first, then to the unit you selected.
Method and factors
result = value × bytes(from) ÷ bytes(to)
- 1 KB = 1,024 bytes
- 1 MB = 1,048,576 bytes (1,024²)
- 1 GB = 1,073,741,824 bytes (1,024³)
- 1 TB = 1,099,511,627,776 bytes (1,024⁴)
Drive manufacturers instead use decimal prefixes, where 1 GB is exactly 1,000,000,000 bytes. That difference is why a "500 GB" drive shows as roughly 465 GB in the operating system: 500 × 10⁹ / 1,073,741,824 = 465.66. Keep the two conventions apart when comparing numbers.
Worked example
Convert 2.5 GB to MB. Bytes: 2.5 × 1,073,741,824 = 2,684,354,560. Divide by the MB factor: 2,684,354,560 / 1,048,576 = 2,560 MB. Equivalent shortcut: 2.5 × 1,024 = 2,560. The calculator shows "2560.000000 MB". Going the other way, 1 TB to GB is 1,024 GB, and 1,500 MB to GB is 1,500 / 1,024 = 1.464844 GB.
Common mistakes and how to interpret the result
- Using 1,000 instead of 1,024. If a vendor or network provider counts in decimal, conversions here will be about 2.4% off per step, and about 10% off by terabytes.
- Mixing bits and bytes. Internet speeds are usually in megabits per second. Divide by 8 to get megabytes. This tool converts bytes only.
- Expecting usable space to equal capacity. File system overhead, formatting and system files reduce the free space you see.
- Reading a rounded answer as exact. Results are rounded to six decimals. Repeating decimals such as 1.464844 are approximations.