GB to TB Converter
Convert gigabytes to terabytes (GB to TB) for drives, backups and cloud storage
1 GB = 0.001 TB, and 1 TB = 1,000 GB. To convert GB to TB, divide the gigabytes by 1,000. In binary units, 1 TiB = 1,024 GiB.
Gigabytes to Terabytes converter
Live1 TB = 1,000 GB, as printed on drive boxes.
- 0.93132257 GiB
- 953.67432 MiB
- 1,000 MB
- 0.0009094947 TiB
- 976,562.5 KiB
How to convert gigabytes to terabytes
A gigabyte is 109 bytes and a terabyte is 1012 bytes. The prefixes giga and tera sit one step apart on the SI ladder, and each step is a factor of 1,000, so turning GB into TB means dividing by 1,000. A 500 GB SSD is 0.5 TB, a 2,000 GB backup set is 2 TB, and an 18,000 GB hard drive is 18 TB. Multiply by 1,000 to go back from terabytes to gigabytes; the data storage converter covers every other step, from single bytes up to petabytes.
Storage makers, cloud providers and NAS vendors all quote capacity this way. The complication appears when an operating system reports the size in binary tebibytes (TiB), where 1 TiB = 1,024 GiB = 1,099,511,627,776 bytes. The difference between the two conventions grows with every prefix, so at the terabyte level it reaches roughly 9%. That is why a new 4 TB drive shows up as about 3.64 TB in Windows. Use the Standard switch above when you need the binary GiB to TiB figure instead. For smaller file sizes, start with the MB to GB converter.
Step by step
- Take the size in gigabytes (GB).
- Divide it by 1,000 to get terabytes (TB).
- For binary TiB, divide the byte count by 1,099,511,627,776 instead.
- Round to two decimal places when comparing drives or plans.
See it on a scale
Worked examples
A phone or laptop SSD, a mid-size backup and a large external hard drive, all expressed in gigabytes.
256 GB ÷ 1,000 = 0.256 TB
= 0.256 TB
750 GB ÷ 1,000 = 0.75 TB
= 0.75 TB
4,000 GB ÷ 1,000 = 4 TB
= 4 TB
How do I convert GB to TB in Excel or Google Sheets?
Put the gigabytes in cell A2 and enter =A2/1000 to get terabytes; =A2*1000 turns terabytes back into gigabytes.
The same pattern handles the binary units that Windows and Linux tools report. The results column shows what each formula returns when A2 holds 4,000:
| Conversion | Formula | Result for 4,000 |
|---|---|---|
| GB to TB | =A2/1000 | 4 |
| TB to GB | =A2*1000 | 4,000,000 |
| GiB to TiB | =A2/1024 | 3.90625 |
| GB to TiB (the Windows “TB”) | =A2*10^9/2^40 | 3.638 |
| GB to GiB (the Windows “GB”) | =A2*10^9/2^30 | 3,725.29 |
To total a column of folder sizes, divide the sum once: =SUM(B2:B40)/1000. Add =ROUND(A2/1000,2) when a report needs two decimals. In Excel, the CONVERT function also understands byte prefixes, so =CONVERT(A2,"Gbyte","Tbyte") gives the same decimal answer.
Google Sheets accepts the same formulas, and it can fill a whole column in one step with =ARRAYFORMULA(, which leaves blank rows empty. In either program, a custom number format such as 0.00" TB" shows the unit next to the value while keeping the cell numeric, so later sums still work.
How long does it take to copy 1 TB?
Copying 1 TB takes 33 min 20 s at a sustained 500 MB/s and 2 h 46 min 40 s at 100 MB/s, because time equals size divided by speed: 1,000,000 MB ÷ the rate in MB/s.
The rates below are typical sequential speeds for each kind of drive or link, not guaranteed figures:
| Drive or link | Assumed rate | 1 TB | 4 TB |
|---|---|---|---|
| USB flash drive or older hard drive | 100 MB/s | 2 h 46 min 40 s | 11 h 6 min 40 s |
| Gigabit Ethernet (1 Gbps, before overhead) | 125 MB/s | 2 h 13 min 20 s | 8 h 53 min 20 s |
| Large 7,200 rpm desktop hard drive | 200 MB/s | 1 h 23 min 20 s | 5 h 33 min 20 s |
| SATA SSD | 550 MB/s | 30 min 18 s | 2 h 1 min 13 s |
| NVMe SSD, PCIe 3.0 x4 | 3,500 MB/s | 4 min 46 s | 19 min 3 s |
| NVMe SSD, PCIe 4.0 x4 | 7,000 MB/s | 2 min 23 s | 9 min 31 s |
A copy only runs as fast as the slower of the two drives, and thousands of small files add overhead for every file. Hard drives also read and write more slowly on their inner tracks, so a full-drive copy averages less than the rated peak. For long jobs, the minutes to hours converter turns the estimate into something easier to plan around.
GB to TB conversion chart
Gigabyte values from memory-card sizes up to data-center scale, converted to decimal terabytes. Values like 1,024 and 2,048 are included because they are easy to confuse with 1 TB and 2 TB.
| Gigabytes (GB) | Terabytes (TB) |
|---|---|
| 1 GB | 0.001 TB |
| 8 GB | 0.008 TB |
| 16 GB | 0.016 TB |
| 32 GB | 0.032 TB |
| 64 GB | 0.064 TB |
| 100 GB | 0.1 TB |
| 128 GB | 0.128 TB |
| 200 GB | 0.2 TB |
| 250 GB | 0.25 TB |
| 256 GB | 0.256 TB |
| 320 GB | 0.32 TB |
| 500 GB | 0.5 TB |
| 512 GB | 0.512 TB |
| 640 GB | 0.64 TB |
| 750 GB | 0.75 TB |
| 1,000 GB | 1 TB |
| 1,024 GB | 1.024 TB |
| 1,500 GB | 1.5 TB |
| 2,000 GB | 2 TB |
| 2,048 GB | 2.048 TB |
| 3,000 GB | 3 TB |
| 4,000 GB | 4 TB |
| 5,000 GB | 5 TB |
| 6,000 GB | 6 TB |
| 8,000 GB | 8 TB |
| 10,000 GB | 10 TB |
| 12,000 GB | 12 TB |
| 14,000 GB | 14 TB |
| 16,000 GB | 16 TB |
| 18,000 GB | 18 TB |
| 20,000 GB | 20 TB |
| 24,000 GB | 24 TB |
| 50,000 GB | 50 TB |
| 100,000 GB | 100 TB |
Gigabytes vs terabytes: what is the difference?
A terabyte is the next decimal step above the gigabyte, so the two units share a system but not a scale. These rows add the details that decide which one you see on a spec sheet.
| Attribute | Gigabytes | Terabytes |
|---|---|---|
| Symbol | GB | TB |
| System | Decimal (SI) | Decimal (SI) |
| Defined as | 1,000 MB | 1,000 GB |
| One unit equals | 0.001 TB | 1,000 GB |
| Exact size in bytes | 1,000,000,000 (109) | 1,000,000,000,000 (1012) |
| Binary counterpart (IEC) | Gibibyte, GiB = 230 = 1,073,741,824 bytes | Tebibyte, TiB = 240 = 1,099,511,627,776 bytes |
| Binary unit is larger by | 7.37% | 9.95% |
| Windows shows one unit as | 0.93 GB (really GiB) | 0.91 TB (really TiB) |
| Typical products | RAM, phone storage, USB sticks, data plans, game installs | Hard drives, SSDs, NAS arrays, cloud backup plans |
4 key differences
- One terabyte contains 1,000 gigabytes, 1,000,000 megabytes and 1012 bytes.
- The tebibyte is 99,511,627,776 bytes larger than the terabyte, while the gibibyte is only 73,741,824 bytes larger than the gigabyte.
- Dividing GB by 1,024 instead of 1,000 understates the terabytes by 2.34%, because it mixes the two conventions.
- Drives and cloud plans are sold in decimal terabytes, while RAM is sold in binary gigabytes, so a 1 TB SSD and 16 GB of memory use different kinds of gigabyte.
What do 1 TB to 24 TB drives show in Windows?
Windows shows a 1 TB drive as 931.32 GB (0.91 TB), a 4 TB drive as 3.64 TB and a 24 TB drive as 21.83 TB. The TB printed on the box is decimal, while Windows divides the same byte count by powers of 1,024 and keeps the GB or TB label. File-system formatting takes a little more space on top of this.
| On the box | Decimal GB | Binary GiB | Binary TiB (shown as TB) |
|---|---|---|---|
| 0.5 TB | 500 GB | 465.66 GiB | 0.45 TiB |
| 1 TB | 1,000 GB | 931.32 GiB | 0.91 TiB |
| 2 TB | 2,000 GB | 1,862.65 GiB | 1.82 TiB |
| 4 TB | 4,000 GB | 3,725.29 GiB | 3.64 TiB |
| 6 TB | 6,000 GB | 5,587.94 GiB | 5.46 TiB |
| 8 TB | 8,000 GB | 7,450.58 GiB | 7.28 TiB |
| 10 TB | 10,000 GB | 9,313.23 GiB | 9.09 TiB |
| 12 TB | 12,000 GB | 11,175.87 GiB | 10.91 TiB |
| 14 TB | 14,000 GB | 13,038.52 GiB | 12.73 TiB |
| 16 TB | 16,000 GB | 14,901.16 GiB | 14.55 TiB |
| 18 TB | 18,000 GB | 16,763.81 GiB | 16.37 TiB |
| 20 TB | 20,000 GB | 18,626.45 GiB | 18.19 TiB |
| 24 TB | 24,000 GB | 22,351.74 GiB | 21.83 TiB |
Why is the TB to TiB gap bigger than the GB to GiB gap?
The gap grows because each binary prefix is 1,024 times the previous one while each decimal prefix is only 1,000 times, so the mismatch compounds with every step. At kilo it is under 2.5%; at tera it is almost 10%.
| Prefix pair | Decimal | Binary | Binary unit is larger by | Decimal size looks smaller by |
|---|---|---|---|---|
| Kilo / kibi | KB = 10³ B | KiB = 2¹⁰ B | 2.4% | 2.34% |
| Mega / mebi | MB = 10⁶ B | MiB = 2²⁰ B | 4.86% | 4.63% |
| Giga / gibi | GB = 10⁹ B | GiB = 2³⁰ B | 7.37% | 6.87% |
| Tera / tebi | TB = 10¹² B | TiB = 2⁴⁰ B | 9.95% | 9.05% |
| Peta / pebi | PB = 10¹⁵ B | PiB = 2⁵⁰ B | 12.59% | 11.18% |
How much fits in 1 TB, 2 TB and 4 TB?
1 TB holds about 250,000 photos at 4 MB each, 104,166 songs at 9.6 MB or 444 hours of 1080p video at 5 Mbps; 2 TB and 4 TB hold twice and four times as much. Counts are whole items, calculated from the stated average sizes in decimal units. Real files vary a lot, so treat these as planning estimates rather than guarantees.
| Content | 1 TB | 2 TB | 4 TB |
|---|---|---|---|
| Photos at 4 MB each | 250,000 | 500,000 | 1,000,000 |
| Songs at 9.6 MB (4 min, 320 kbps MP3) | 104,166 | 208,333 | 416,666 |
| Hours of 1080p video at 5 Mbps (2.25 GB/h) | 444 | 888 | 1,777 |
| Hours of 4K video at 15 Mbps (6.75 GB/h) | 148 | 296 | 592 |
| Games at 100 GB each | 10 | 20 | 40 |
How do you plan backups and RAID capacity in TB?
Plan in terabytes by adding up the folders you need to protect in gigabytes, dividing by 1,000 and then buying at least twice that capacity, so the backup still fits as your data grows. Once the total runs into hundreds of gigabytes, terabytes are simply the easier unit to compare with drive sizes.
RAID usable capacity
In a NAS, the usable space depends on the RAID level. Two 4 TB drives in RAID 1 mirror each other, giving 4 TB usable. Four 8 TB drives in RAID 5 give up one drive's worth of space for parity, leaving 24 TB, which the NAS will report as about 21.83 TiB. Six 10 TB drives in RAID 6 keep two drives for parity, leaving 40 TB, or about 36.38 TiB.
The 3-2-1 rule
Keep three copies of important data, on two different kinds of storage, with one copy off site. If your photo library is 1,200 GB (1.2 TB), that means at least one 2 TB external drive plus a cloud plan or a second drive stored elsewhere.
Moving terabytes over a network takes time: a full 1 TB transfer on a 1 Gbps link needs at least 8,000 seconds, about 2 h 13 min. The Gbps to Mbps converter and the seconds to minutes converter help with the math.
What are a gigabyte and a terabyte?
A gigabyte (GB) is one billion bytes. It became the everyday unit for RAM, phone storage and mobile data in the 2000s. A terabyte (TB) is one trillion bytes, or 1,000 GB, and is now the standard size class for hard drives, SSDs and backup systems. Both prefixes were adopted into the SI in 1960.
The IEC introduced the binary names in 1998 so that powers of two had their own units: the gibibyte (GiB, 230 bytes) and the tebibyte (TiB, 240 bytes). Linux tools and cloud virtual machine specs often use them explicitly. Above the terabyte come the petabyte (1,000 TB), exabyte, zettabyte, yottabyte and, since 2022, the ronnabyte and quettabyte. The whole ladder is on the data storage converter.
Sources and further reading
The standards and references behind the numbers on this page. Links open in a new tab.
Standards and official sources
Further reading
- GigabyteWikipedia
GB to TB FAQs
Short, exact answers to what people ask most.
How many GB are in a TB?
One terabyte is 1,000 gigabytes in decimal units, which is how drives and cloud plans are sold. One tebibyte (TiB) is 1,024 gibibytes (GiB).
How many TB is 2,000 GB?
2,000 GB is exactly 2 TB. The same 2,000,000,000,000 bytes are about 1.82 TiB, which is what Windows shows as TB.
Is 1 TB 1,000 GB or 1,024 GB?
Under the SI and IEC standards, 1 TB is 1,000 GB. The 1,024 figure applies to the binary units: 1 TiB equals 1,024 GiB.
Why does my 4 TB drive show about 3.6 TB?
The drive holds 4,000,000,000,000 bytes. Windows divides by 1,024 four times, giving about 3.64 TiB, and labels it TB. No space is missing.
How many photos fit in 1 TB?
At an average of 4 MB per photo, 1 TB holds about 250,000 photos. Larger RAW files of 25 MB each would fit about 40,000.
Is 512 GB half a terabyte?
In decimal units 512 GB is 0.512 TB, slightly more than half. The number 512 comes from binary sizing, where 512 GiB is exactly half of 1 TiB.
How many TB is 500 GB?
500 GB is 0.5 TB. Windows would report the same 500,000,000,000 bytes as about 465.66 GB, or 0.45 TB.
How many GB is 2 TB?
2 TB is 2,000 GB in decimal units. In binary units the same drive holds about 1,862.65 GiB, which Windows labels GB.
How many TB is 10,000 GB?
10,000 GB is exactly 10 TB, or about 9.09 TiB in binary units.
Related conversions
Decimal prefixes from the BIPM SI Brochure (9th edition), binary prefixes from IEC 80000-13:2008, the 2022 ronna and quetta prefixes from CGPM Resolution 3 (27th meeting), the Gigabit Ethernet rate from IEEE 802.3, and the CONVERT function from Microsoft's Excel documentation. Last updated . How we verify our numbers.