You can also type a size with its unit, such as 500 GB or 1.5 TiB.
Converted
Decimal and binary units
There are two ways to count large amounts of data. Decimal (SI) units step by 1,000: a kilobyte (kB) is 1,000 bytes, a gigabyte (GB) a billion. Drive makers, network speeds and most cloud bills use these. Binary (IEC) units step by 1,024: a kibibyte (KiB) is 1,024 bytes, a gibibyte (GiB) 1,073,741,824. Memory, Linux tools such as df -h and free -h, and Windows (which labels them GB) count this way.
The gap grows with each step: 2.4% at kilo, 7.4% at giga, 10% at tera and 12.6% at peta.
Why a 1 TB drive shows 931 GB
A 1 TB drive holds 1,000,000,000,000 bytes. Divided by 1,024³ that is 931.3 GiB, which Windows displays as “931 GB”. Nothing is missing: the drive is measured in decimal units and shown in binary ones. File systems then reserve a little more for their own structures.
Bits and bytes
A byte is 8 bits. Network speeds are quoted in bits per second with a lower-case b (Mbps, Gbps), storage in bytes with a capital B. To turn a 1 Gbit link into storage terms divide by 8: 125 MB a second. This page converts sizes only; for how long a transfer takes, use the Bandwidth Calculator. All conversions happen in your browser.