GB to TB converter

What are GB and TB?

Gigabyte (GB) and terabyte (TB) are units of digital storage used to quantify the capacity of devices like hard drives, USB flash drives, and cloud storage. These terms belong to two distinct measurement systems:

1. Base-10 (SI System): Follows the International System of Units, where units increase by powers of 10.
2. Base-2 (IEC Standard): Uses binary prefixes, adhering to the International Electrotechnical Commission (IEC) standard, where units increase by powers of 2.

Confusion arises because manufacturers often use these terms interchangeably, despite their mathematical differences.

The two systems of data measurement

1. Base-10 (SI system)

In this system, storage units are defined using decimal (base-10) notation:

• 1 megabyte (MB) = $10^6$ bytes = 1,000,000 bytes
• 1 gigabyte (GB) = $10^9$ bytes = 1,000,000,000 bytes
• 1 terabyte (TB) = $10^{12}$ bytes = 1,000,000,000,000 bytes

This system is commonly used by storage manufacturers and internet service providers.

2. Binary prefixes (IEC standard)

Computers operate using binary logic, so the IEC introduced base-2 prefixes in 1998 to avoid ambiguity. While the underlying unit (bytes) is decimal, the prefixes follow binary scaling:

• 1 mebibyte (MiB) = $2^{20}$ bytes = 1,048,576 bytes
• 1 gibibyte (GiB) = $2^{30}$ bytes = 1,073,741,824 bytes
• 1 tebibyte (TiB) = $2^{40}$ bytes = 1,099,511,627,776 bytes

Operating systems like Windows often display storage in GiB or TiB but label them as GB or TB, leading to discrepancies. Note that some industries, like RAM manufacturing, still informally use base-2 definitions despite the IEC standard.

Formula for conversion

To convert between units, use these formulas:

Base-10 (SI) conversions

• GB to TB:

• TB to GB:

Base-2 (IEC) conversions

• GiB to TiB:

• TiB to GiB:

Examples of conversions

Example 1: Base-10 (SI)

A 4 TB hard drive advertised by a manufacturer uses base-10 units. To find its capacity in GB:

Example 2: Base-2 (IEC)

If your computer shows 1.81 TiB of free space, convert this to GiB:

Example 3: Mixed Systems

A 256 GB SSD (base-10) will display as approximately 238.42 GiB in Windows (base-2):

Why do these differences matter?

• Purchasing storage: A 1 TB drive (base-10) offers 1,000 GB, but your computer may report it as ~931 GiB.
• File transfers: Downloading a 100 GB file (base-10) requires 93.13 GiB (base-2) of space.
• Cloud services: Providers may use base-10 units, while your device uses base-2, causing apparent discrepancies.

Historical context

Before 1998, the term “gigabyte” was often used ambiguously for both $10^9$ and $2^{30}$ bytes. The IEC standardized base-2 units (e.g., GiB, TiB) to resolve this confusion. However, adoption remains inconsistent, with many software tools still using SI labels for binary units. Notably, industries like RAM manufacturing continue to use base-2 definitions informally, despite the IEC standard.

Frequently asked questions

How many GB are in a TB?

In the SI system:

In the IEC system:

Why does my 1 TB hard drive show only 931 GB?

Manufacturers use base-10 (1 TB = 1,000 GB), but computers use base-2 (1 TB ≈ 931 GiB). The difference arises from:

How to convert 5,000 GB to TB?

Using base-10:

Is a gigabyte larger than a gibibyte?

No. A gigabyte (GB) is smaller than a gibibyte (GiB). 1 GB = 1,000,000,000 bytes, while 1 GiB = 1,073,741,824 bytes. Thus, 1 GB ≈ 0.931 GiB.

How much storage is 2 TiB in TB?

Convert TiB to GiB first:

Then convert GiB to GB (approximate):

Notes

• Always check the context (base-10 vs. base-2) when comparing storage capacities.
• Use online converters that specify the standard (SI or IEC) for accuracy.
• For programming or engineering, prefer GiB/TiB to avoid ambiguity.