How to convert gigabytes to terabytes
One gigabyte equals 0.001 terabytes, so multiply the number of gigabytes by 0.001:
TB = GB × 0.001
GB = TB ÷ 0.001 (1 TB = 1,000 GB)
Example: 256 GB → 256 × 0.001 = 0.256 TB.
Going the other way, divide by 0.001, or multiply by 1,000; the terabytes to gigabytes converter does it for you.
Everyday values
| Gigabytes | Terabytes | For example |
|---|---|---|
| 256 GB | 0.256 TB | a phone's storage |
| 500 GB | 0.5 TB | a laptop SSD |
| 1,000 GB | 1 TB | one terabyte |
| 2,000 GB | 2 TB | 2 TB |
When you need this conversion
One terabyte is 1,000 gigabytes in decimal units. A 1 TB drive can hold roughly 250,000 photos of 4 MB each.
Gigabyte to terabyte conversion table
| GB | TB | GB | TB |
|---|---|---|---|
| 100 GB | 0.1 TB | 1,100 GB | 1.1 TB |
| 200 GB | 0.2 TB | 1,200 GB | 1.2 TB |
| 300 GB | 0.3 TB | 1,300 GB | 1.3 TB |
| 400 GB | 0.4 TB | 1,400 GB | 1.4 TB |
| 500 GB | 0.5 TB | 1,500 GB | 1.5 TB |
| 600 GB | 0.6 TB | 1,600 GB | 1.6 TB |
| 700 GB | 0.7 TB | 1,700 GB | 1.7 TB |
| 800 GB | 0.8 TB | 1,800 GB | 1.8 TB |
| 900 GB | 0.9 TB | 1,900 GB | 1.9 TB |
| 1,000 GB | 1 TB | 2,000 GB | 2 TB |
About the units
- Gigabyte (GB): 1,000,000,000 bytes (SI prefix).
- Terabyte (TB): 10¹² bytes (SI prefix).
Both are units of digital storage. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many terabytes are in one gigabyte?
One gigabyte is 0.001 terabytes. One terabyte is 1,000 gigabytes.
How do I convert gigabytes to terabytes?
Multiply the value in gigabytes by 0.001. To go back, divide by 0.001.
What is 256 GB in terabytes?
256 GB = 0.256 TB.
What is 500 GB in terabytes?
500 GB = 0.5 TB.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.