Data Size Converter (MB, GB, GiB)

Data Size Converter converts amounts of digital data between bits, bytes and their multiples, keeping the two systems apart. The decimal units — kilobyte, megabyte, gigabyte, terabyte, petabyte — go up in thousands, and are what drive makers, phone storage and internet plans use. The binary units — kibibyte, mebibyte, gibibyte, tebibyte — go up in 1,024s, and are what Windows and many apps actually count in, even when they label the result “GB”. That gap is why a 1 TB drive shows as about 931 GB on a computer: nothing is missing, it is 931 GiB. The converter also handles bits, which internet speeds are quoted in: 100 Mbit/s is 12.5 megabytes a second, before overheads. All conversions are exact.

1. Type the amount.
2. Choose its unit and the one you want, or press a common conversion such as TB → GiB.
3. Read the answer and every other unit in the table.

• Download times also depend on protocol overheads and the server, so 100 Mbit/s rarely delivers a full 12.5 MB every second.
• Some older software and memory makers use “KB”, “MB” and “GB” for the binary sizes. Check which one a figure means before relying on the last few per cent.
• A formatted drive also loses some space to the file system and to recovery partitions, on top of the decimal–binary difference.
• Data rates (per second) and sizes use the same units here; add “per second” yourself.
• The conversion happens in your browser; nothing is sent.

The maker counts 1,000,000,000,000 bytes; the computer divides by 1,024 three times and calls the result GB. 10¹² bytes is 931.32 GiB — the same space.

1,000 MB in decimal units. In binary units, 1 GiB is 1,024 MiB.

12.5 megabytes per second at most, because a byte is 8 bits. Real downloads are a little slower.

A small b means bits, a capital B bytes. 8 Mb (megabits) is 1 MB (megabyte).