TB to GB Converter
1 TB = 1,000 GB decimal, or 1,024 GB binary. Switch below.
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A thousand gigabytes, or 1,024
Decimal gives 1,000 gigabytes to the terabyte; binary gives 1,024. The difference is 2.4 % at this single step, but it compounds with the two steps below it — which is why a 1 TB drive reports as 931 GB rather than 976.
1 TB = 1,000 GB (decimal) or 1,024 GB (binary)
When planning storage, work in whichever convention your tools report and leave headroom. Mixing the two is where capacity plans go wrong.
The terabyte
A million million bytes decimal, or about 1.0995 million million binary — a difference of 9.95 %. This is where the two conventions diverge enough to cause complaints: a 1 TB drive reports as 931 GB.
Nothing is missing from the drive. The manufacturer counted in powers of ten and the operating system is counting in powers of two.
The gigabyte
A thousand million bytes decimal, or 1,073,741,824 binary. The gap has grown to 7.4 % by this point, which is why a drive sold as 500 GB shows up as about 465 in Windows.
A gigabyte is roughly a couple of hours of standard-definition video, or about 250 songs.
The working, step by step
Every line updates with whatever you type above. The point is the method, which is the same for any pair of units in this family.
The same quantity, two different numbers
One physical amount, read off two scales. The tick marks do not line up, and the gap between them is the conversion factor made visible.
How much is that?
A number is easier to judge next to something familiar.
Your turn
Reading a method and being able to use it are different things. Answer within half a per cent and it counts as correct.
Score: 0 of 0
How to use this converter
- Type into either box. The other side updates as you go; there is no button to press.
- Swap the direction with the button between the boxes, carrying your value across.
- Set the decimals if the default is more or less precision than you need.
- Copy the answer with its unit, ready to paste.
- Use the shortcut buttons for the values that come up most often.
- Share the result. The address bar tracks what you type, so the link you copy opens on the same number.
Common uses and tips
Where these conversions come up
- Buying storage. A drive sold as 1 TB shows up as 931 GB in Windows. Nothing is missing; the two are counting in different bases.
- Upload limits. Attachment and upload caps are stated in MB, and file managers report sizes in MB too — but not always the same MB.
- Mobile data. Allowances are in GB, app usage is reported in MB.
- Broadband speed. Sold in megabits, downloaded in megabytes, eight times apart.
- Backups and disk planning, where a few per cent of convention error compounds into real numbers at terabyte scale.
The big one: decimal against binary
There are two conventions, and both are in daily use.
- Decimal. A kilobyte is 1,000 bytes, a megabyte 1,000,000, a gigabyte 1,000,000,000. This is what the SI prefixes actually mean, and what storage manufacturers use.
- Binary. A kilobyte is 1,024 bytes, a megabyte 1,048,576, a gigabyte 1,073,741,824. Memory is built in powers of two, so this is what operating systems grew up using.
The gap widens with every step: 2.4 % at kilobytes, 4.9 % at megabytes, 7.4 % at gigabytes, 9.95 % at terabytes. That is why a 1 TB drive reports as 931 GB — a difference of 69 GB that looks like missing capacity and is not.
The standards bodies resolved this in 1998 by inventing separate binary prefixes: KiB, MiB, GiB and TiB for the powers of two, leaving KB, MB, GB and TB for the powers of ten. Linux mostly adopted them. Windows did not, and still labels binary quantities with decimal names.
Bits and bytes
Eight bits make a byte. Capitalisation is the only thing distinguishing them: Mb is megabits, MB is megabytes.
Network speeds are sold in bits and files are measured in bytes, which is why a 100 Mbps connection downloads at about 12.5 MB/s. The connection is not underperforming; the units differ by a factor of eight.
Tips worth knowing
- Bitrates are always decimal. A kilobit per second is 1,000 bits per second, never 1,024. The binary ambiguity affects storage, not speed.
- RAM is always binary. An 8 GB memory module is 8 GiB — 8,589,934,592 bytes — because memory is addressed in powers of two.
- Check which convention a figure uses before comparing two of them. Comparing a decimal number with a binary one is where the confusion starts.
Values people look up most
Each one opens the converter with the number already in it.
- 0.5 TB to GB
- 1 TB to GB
- 1.5 TB to GB
- 2 TB to GB
- 3 TB to GB
- 4 TB to GB
- 5 TB to GB
- 6 TB to GB
- 8 TB to GB
- 10 TB to GB
- 12 TB to GB
- 14 TB to GB
- 16 TB to GB
- 18 TB to GB
- 20 TB to GB
- 24 TB to GB
- 32 TB to GB
Quick reference
Decimal convention: 1,000 GB to the TB.
| Terabytes | Gigabytes |
|---|---|
| 0.5 TB | 500 GB |
| 1 TB | 1,000 GB |
| 2 TB | 2,000 GB |
| 4 TB | 4,000 GB |
| 6 TB | 6,000 GB |
| 8 TB | 8,000 GB |
| 10 TB | 10,000 GB |
| 16 TB | 16,000 GB |
| 20 TB | 20,000 GB |
| 32 TB | 32,000 GB |
Questions people ask
How many GB in a TB?
1,000 decimal, 1,024 binary.
What is 4 TB in GB?
4,000 GB decimal, or 4,096 GB binary.
Why does the difference look bigger than 2.4 %?
Because the conversion from bytes to gigabytes has already applied the same 2.4 % twice more. The errors compound.