The terabyte is the unit on the box your external drive came in — the scale of photo libraries, video projects, and game installs that filled the old gigabyte world. In the binary convention this converter follows, one terabyte equals 1,024 gigabytes, which unfolds to 1,048,576 megabytes and 1,099,511,627,776 bytes, while 1,024 terabytes roll up into a single petabyte (1 TB is 1/1024 PB). Enter 1 in the Terabytes (TB) box and the Gigabytes (GB) readout shows 1,024, the Megabytes (MB) box shows 1,048,576, and the raw Bytes figure stretches to twelve digits. The perspective number: a terabyte holds roughly 250,000 MP3 songs or about 500 hours of HD video, which is why "how many TB do I need" is the first question of every backup plan. The honest caveat from the storage aisle: drive makers often label decimally (1 TB = 1,000 GB), so your "4 TB" drive shows about 3.64 TiB in the operating system — same drive, different ruler.

With the pre-filled defaults — Terabytes (TB) 1 — the Terabyte Converter returns Gigabytes (GB) 1,024.00, Megabytes (MB) 1,048,576.00, Petabytes (PB) 0.000977, Bytes 1,099,511,627,776. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.