TB to GB Converter
Convert terabytes to gigabytes — a thousand gigabytes to the terabyte in decimal units. Results update as you type; exact factors shown.
One terabyte (10¹²) is 1,000 gigabyte (10⁹) — see the exact factor, not a rounded rule of thumb.
How the tb to gb converter works
Storage converts through the byte (8 bits). Drive makers and network speeds use decimal prefixes (1 GB = 10⁹ bytes); operating systems often report binary units (1 GiB = 2³⁰ = 1,073,741,824 bytes) — sometimes labelled "GB". The gap is 7.4% at the gigabyte and 10% at the terabyte.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common data conversions
| From | To | Units |
|---|---|---|
| 0.25 TB | 250 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 0.5 TB | 500 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 1 TB | 1,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 2 TB | 2,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 4 TB | 4,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 6 TB | 6,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 8 TB | 8,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 10 TB | 10,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 12 TB | 12,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 16 TB | 16,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 20 TB | 20,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
| 100 TB | 100,000 GB | terabyte (10¹²) to gigabyte (10⁹) |
Units in this converter and their exact factors
| Unit | Symbol | One unit in bytes |
|---|---|---|
| bit | bit | 0.125 byte |
| byte | B | 1 byte |
| kilobyte (10³) | kB | 1,000 byte |
| megabyte (10⁶) | MB | 1,000,000 byte |
| gigabyte (10⁹) | GB | 1,000,000,000 byte |
| terabyte (10¹²) | TB | 1,000,000,000,000 byte |
| kibibyte (2¹⁰) | KiB | 1,024 byte |
| mebibyte (2²⁰) | MiB | 1,048,576 byte |
| gibibyte (2³⁰) | GiB | 1,073,741,824 byte |
| tebibyte (2⁴⁰) | TiB | 1,099,511,627,776 byte |
FAQFrequently asked questions about data conversion
How many GB in a TB?
1,000 decimal, or 1,024 GiB binary.
Why does my 2 TB drive show 1.81 TB?
Because the operating system divides by 1,024 rather than 1,000 at each step — the drive really does hold 2 trillion bytes.
How much is a terabyte?
Roughly 250,000 photos or 40 hours of 4K video.
Should I buy in decimal or binary?
You buy decimal, because that is how drives are sold; size your filesystems in binary, because that is what they report.
What comes after a terabyte?
A petabyte, a thousand terabytes.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.