Gigabytes to Terabytes Converter

The converter divides by 1,000, because here a terabyte is 1,000 GB. That is also how drive capacities are printed on the box, so your total and the drive label speak the same language as long as your folder sizes are decimal too.

Say your photo library is 750 GB and your videos take 1,400 GB. Together that's 2,150 GB, or 2.15 TB. A 2 TB drive won't hold it; the next size up will, with room to grow.

Folder sizes shown by a system that counts in 1,024s are really gibibytes, even when the screen says GB. Converting those as plain gigabytes makes your data look smaller than it is. Pick Gibibytes in the From list to get the true size in TB:

The last row is the trap. 1,900 "GB" looks as if it fits on a 2 TB drive, but if those are gibibytes it is 2.0401 TB and it does not.

A drive never offers its full printed capacity for your files. Formatting sets aside space for the file system itself, and backup software that keeps older versions of files grows over time. Plan for a total comfortably below the drive's size rather than one that just squeezes in. The converter tells you the size of your data; the margin you leave is your call.

For decimal figures, move the decimal point three places to the left: 3,000 GB is 3 TB and 640 GB is 0.64 TB. That's all the converter does with these two units.

For a figure that came from a 1,024-based system, divide by 931.32 instead. 1,900 of those "GB" divided by 931.32 gives 2.04 TB, which matches the converter's GiB → TB result. Keeping both divisors in mind saves you from buying a drive that's one size too small. When in doubt, use the 931.32 divisor, since it gives the larger, safer total.