💾 TB to GB Converter

What is the TB to GB Converter?

Unlike a KB to GB conversion, which passes through MB along the way, a tb to gb converter only needs one step, because terabyte and gigabyte sit right next to each other on the digital storage ladder. In the binary convention used by most operating systems, 1 TB equals 1,024 GB, because computers address memory and storage in powers of two (2 to the 10th power is 1,024). In the decimal convention used by drive manufacturers and the SI system, 1 TB equals a flat 1,000 GB, because that convention counts in powers of ten.

This single-step difference is exactly why a "2 TB" external drive shows up in Windows or macOS as roughly 1.81 TB, or equivalently why its capacity in GB looks smaller than expected once the operating system reports it. The manufacturer sold you 2,000,000,000,000 bytes, which is genuinely 2 TB under the decimal definition, but your file manager divides that same byte count by 1,024 three times (TB to GB to MB to KB, or more precisely by 1,024 cubed against the byte total) to get its binary GB and TB figures, and the result is a smaller number even though not a single byte is missing.

The IEC tried to fix this ambiguity by introducing tebibyte (TiB) and gibibyte (GiB) as unambiguous binary units, defining 1 TiB as exactly 1,024 GiB, and leaving TB and GB free to mean the decimal 1,000 and 1,000,000,000,000 bytes respectively. In practice almost no consumer software uses TiB or GiB, so "TB" and "GB" are used loosely for both meanings, and the only reliable way to know which one applies is to check where the number came from: an operating system, RAM spec, or backup software size is almost always binary, while a hard drive, SSD, NAS, or cloud storage plan sold by a manufacturer is almost always decimal.

A reliable tb to gb converter has to let you pick the standard rather than assuming one, because both are used constantly and interchangeably in everyday storage decisions. Whether you are sizing a NAS array, checking if a video export will fit on a portable SSD, or working out how many gigabyte-sized backups fit inside a terabyte cloud storage plan, getting the binary/decimal choice right is the difference between a number that matches what you see on screen and one that is off by roughly 7 percent.

When to use it

• Checking whether a video project, photo library, or backup set, listed in GB, will fit on a drive or cloud plan advertised in TB.
• Converting a hard drive, SSD, or NAS capacity between the manufacturer decimal rating and the binary figure your operating system reports.
• Working out how many gigabyte-sized backups, VM images, or datasets add up to a terabyte when planning storage capacity.
• Explaining or double-checking why a "storage size mismatch" between a spec sheet and your file manager is not a bug, just two different counting conventions.

How to use the TB to GB Converter

1. Choose Binary (1 TB = 1,024 GB) if you are matching an operating system file or drive size, or Decimal (1 TB = 1,000 GB) if you are matching a manufacturer spec or SI-based figure.
2. Type a value into the Terabytes field to see the equivalent in gigabytes appear instantly.
3. Or type a value into the Gigabytes field to see the equivalent in terabytes instead, the converter works in both directions from the same fields.
4. Use the Copy button to copy the result line to your clipboard for pasting into a document, ticket, or spreadsheet.

Formula & method

Worked examples

Common TB to GB conversions (binary, 1 TB = 1,024 GB)

Same values converted with the decimal standard (1 TB = 1,000 GB)

Common mistakes to avoid

• Assuming there is only one correct factor. Both 1,024 and 1,000 are legitimate, they just belong to different conventions (binary/JEDEC vs decimal/SI). Using the wrong one when checking a drive size against an operating system or a spec sheet will produce a mismatch that looks like an error but is not.
• Treating the drive-size gap as missing storage. A "2 TB" drive rated by the manufacturer in decimal (2,000,000,000,000 bytes) will show as roughly 1.81 TB in an operating system that reports capacity in binary. No storage is missing; the two numbers are just answers to different questions.
• Confusing this with the KB-to-GB two-step conversion. TB to GB is a single step (multiply or divide once by 1,024 or 1,000), unlike KB to GB, which passes through MB and uses the factor squared. Applying a squared factor here will overstate the result by a huge margin.
• Rounding too early. When converting a large batch of GB values back to TB, rounding intermediate results before the final division compounds small errors. Keep full precision through the calculation, or let a tb to gb converter handle it directly, as this one does.

Glossary

Terabyte (TB)

A unit of digital storage equal to 1,024 GB (binary convention) or 1,000 GB (decimal convention).

Gigabyte (GB)

A unit of digital storage equal to 1,024 MB (binary convention) or 1,000 MB (decimal convention), and the unit most drives and files are compared against a TB in.

Binary (JEDEC) standard

Counts storage in powers of two, so 1 TB = 1,024 GB. Used by most operating systems when they report file and disk sizes.

Decimal (SI) standard

Counts storage in powers of ten, so 1 TB = 1,000 GB. Used by drive manufacturers and cloud storage plans.

Tebibyte (TiB)

The IEC term that unambiguously means 1,024 GiB, introduced to separate the binary meaning from TB, though it is rarely used outside technical documentation.

Byte

The base unit of digital storage; 1 TB equals either 2^40 bytes (binary, about 1.0995 trillion bytes) or 10^12 bytes (decimal, exactly 1 trillion bytes).

Frequently asked questions