Calculator
What the GB to TB does
GB to TB: 1 GB = 0.001 TB, so multiply a gigabyte (1000 MB) value by 0.001 to get terabyte (1000 GB), or divide to go back. Example: 1 GB = 0.001 TB.
Result, How it was calculated and Reverse conversion, derived from Value, From and To. Edit a field and the answer updates in place.
Typical users are anyone working across two measurement systems. Having the exact factor matters more than a rough mental estimate.
There is no back end here. The calculation runs where you are sitting, not on a server somewhere.
If you want to check the arithmetic, the field table, the method and a worked example are further down.
What do the GB to TB fields mean?
The GB to TB uses 3 inputs. You can work from the defaults, or clear them and start fresh, both work.
| Field | What to enter | Default |
|---|---|---|
| Value | required | 1 |
| From | choose from Bit (b), Byte (B), Kilobyte (1000 B) (kB), Megabyte (1000 kB) (MB), Gigabyte (1000 MB) (GB) or Terabyte (1000 GB) (TB) | Gigabyte (1000 MB) (GB) |
| To | choose from Bit (b), Byte (B), Kilobyte (1000 B) (kB), Megabyte (1000 kB) (MB), Gigabyte (1000 MB) (GB) or Terabyte (1000 GB) (TB) | Terabyte (1000 GB) (TB) |
How does the GB to TB work?
Both units are converted through data's base unit (byte), so any of the 11 units in the dropdowns can be paired in either direction without loss of accuracy.
Factors follow the internationally agreed definitions. The inch has been exactly 25.4 mm since 1959, and an exact definition is used wherever one exists. Where a unit is fixed by measurement rather than by agreement, the accepted CODATA or IAU value is used.
Worked example
These are the values the GB to TB loads by default, and the result it produces from them. Here is the calculation as it stands the moment the page loads.
| Value | 1 |
|---|---|
| From | Gigabyte (1000 MB) (GB) |
| To | Terabyte (1000 GB) (TB) |
| Result | 0.001 TB |
|---|---|
| How it was calculated | 1 GB = 0.001 TB, so 1 × 0.001 = 0.001 TB |
| Reverse conversion | 1000 GB (if you meant 1 TB) |
Gigabytes and terabytes
1 terabyte (decimal) equals exactly 1,000 gigabytes (10¹² bytes); the binary tebibyte (TiB) equals 1,024 gibibytes (2⁴⁰ bytes, about 1.0995 × 10¹² bytes). The gap has now grown to about 10%, the largest relative discrepancy yet at this scale.
Worth knowing
- A drive or cloud-storage plan advertised as "2 TB" (decimal) will show as roughly 1.82 TiB in an operating system that reports binary values under a decimal-looking label: a meaningful-looking "missing" 180+ GB that is, again, purely a counting-convention artefact.
- Cloud storage providers and data-centre specifications are increasingly explicit about using true decimal terabytes for billing and capacity claims, precisely because the gap at this scale is large enough that ambiguity becomes a real customer-complaint driver.
- Large media libraries (4K video archives, professional photography backups) are commonly measured in terabytes today, making this one of the more practically relevant conversions in the data category for consumers, not just IT professionals.
Definitions: BIPM SI Brochure · NIST reference on units
How to use it
- Fill in Value.
- Pick a value for From: the options are Bit (b), Byte (B), Kilobyte (1000 B) (kB), Megabyte (1000 kB) (MB), Gigabyte (1000 MB) (GB) or Terabyte (1000 GB) (TB).
- Pick a value for To: the options are Bit (b), Byte (B), Kilobyte (1000 B) (kB), Megabyte (1000 kB) (MB), Gigabyte (1000 MB) (GB) or Terabyte (1000 GB) (TB).
- Watch the results panel as you type: it recalculates on every keystroke.
- The panel reports Result, How it was calculated and Reverse conversion.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Repeated conversions compound rounding, so convert once from the original value where possible.
- Factors use the internationally agreed definitions; some industries round them differently.
- The output is a number, not a judgement. Deciding what it means is still your job.
- The tool cannot tell whether a number was entered in the unit you intended, so double-check the labels.
Frequently asked questions
Value, From and To. That is the whole form. Nothing starts empty, letting you treat it as a what-if tool rather than a data-entry form.
With the values loaded when the page opens, result comes out as 0.001 TB. Any edit re-runs the calculation, so there is no stale number on screen.
Nothing leaves your machine. The only network traffic is loading the page itself.
Nothing at all. There is no registration, no paywall and no per-use quota.
Reliable for the case described. Where more than one convention exists, the method section says which one is used.