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Gigabytes to terabytes

Multiply gigabytes by 0.001 to get terabytes.

1 GB = 0.001 TBIEC 80000-13
GB
2TB

2,000 GB = 2 TB

How to convert gigabytes to terabytes

The terabyte is one trillion bytes (10¹² B) in the decimal convention. The gigabyte is one billion bytes (10⁹ B) in the decimal convention.

Worked example — 2,000 GB: 2,000 × 0.001 = 2 TB.

Gigabytes to terabytes table

Common conversions. The reverse table is on terabytes to gigabytes.
GigabytesTerabytes
100 GB0.1 TB
250 GB0.25 TB
500 GB0.5 TB
1,000 GB1 TB
2,000 GB2 TB
4,000 GB4 TB
8,000 GB8 TB
16,000 GB16 TB
32,000 GB32 TB

Reverse and related

About gigabytes and terabytes

Gigabyte (GB)

1 GB = 0.001 TB

Definition. One billion bytes (10⁹ B) in the decimal convention

History and origin

The gigabyte uses the metric giga prefix for a billion bytes. Drive makers label capacity in decimal gigabytes, while operating systems often report the binary gibibyte, which is why sizes seem to disagree.

Current use

Gigabytes measure phone storage, memory and mobile data plans.

Source: IEC 80000-13 (quantities and units — information science); NIST on binary prefixes

Terabyte (TB)

1 TB = 1,000 GB

Definition. One trillion bytes (10¹² B) in the decimal convention

History and origin

The terabyte, a trillion bytes, became an everyday size as hard drives grew through the 2000s. As with smaller units, the decimal value differs from the binary tebibyte.

Current use

Terabytes measure hard drives, large media libraries and backups.

Source: IEC 80000-13 (quantities and units — information science); NIST on binary prefixes

Where people use this

Gigabytes: phone storage, mobile data plans. Terabytes: hard drives, backups. 1000 GB is 1 TB.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 TB = 1,000 GB, so 1 GB = 1 ÷ 1,000 = 0.001 TB.

Every value is carried to full double precision; the display is rounded.

Both units are defined in IEC 80000-13 (quantities and units — information science); NIST on binary prefixes.

Questions people ask

How many GB in a TB?

One terabyte is 1000 gigabytes in the decimal convention. To convert TB to GB, multiply by 1000.

How many GB is 2 TB?

2 TB is 2000 GB, and 4 TB is 4000 GB.

How many GB is half a TB?

Half a terabyte is 500 GB.

Why does a 1 TB drive show less than 1000 GB?

Operating systems report binary units, so a 1 TB decimal drive shows as about 931 GiB, which it labels GB.

All gigabyte conversions