TB to PB Converter
Type a size in terabytes and read it in petabytes. The box divides by 1,000; clear the SI box to divide by 1,024.
Published by the Reeliy Editorial Team. Last updated: Oct 22, 2026
How many terabytes are in a petabyte?
1 TB = 1,000 PB in SI counting, the system that the International System of Units defines and storage vendors use. In binary counting 1 TiB = 1,024 PiB; the binary units carry the IEC names tebibytes and pebibytes.
PB = TB × 1,000 (SI)
PiB = TiB × 1,024 (binary)
The converter opens with Use SI standard ticked. Clear the box to count in powers of 1,024; the labels then change to TiB and PiB, so you can tell which system an answer belongs to.
Where TB to PB comes up
Fleet and capacity planning is done in terabytes, one disk or shelf at a time, but budgets, contracts and press releases are quoted in petabytes. Adding up terabytes and restating the total as petabytes is the usual route from an inventory sheet to a headline figure.
How to convert TB to PB
- Type the number of terabytes in the first box.
- Leave Use SI standard ticked for thousands, or clear it for 1,024s.
- The PetaBytes box shows the answer as you type.
The digits are computed exactly, not through floating-point numbers, so very large sizes keep every digit. Answers of 0.1 or more are rounded to four decimal places and smaller ones keep six significant digits. Anything beyond 100 digits or a power of ten above 100 reads "Number too large".
Example: 2500 TB
Take 2500 TB. In SI counting that is 2500 × 1,000 = 2,500,000 PB. In binary counting it is 2500 × 1,024 = 2,560,000 PiB, using TiB and PiB.
TB to PB table
| TeraBytes (TB) | PB, SI (× 1,000) | PiB, binary (× 1,024) |
|---|---|---|
| 1 | 1,000 | 1,024 |
| 10 | 10,000 | 10,240 |
| 100 | 100,000 | 102,400 |
| 500 | 500,000 | 512,000 |
| 1,000 | 1,000,000 | 1,024,000 |
| 2,000 | 2,000,000 | 2,048,000 |
| 5,000 | 5,000,000 | 5,120,000 |
| 10,000 | 10,000,000 | 10,240,000 |
| 50,000 | 50,000,000 | 51,200,000 |
The opposite direction is the PB to TB converter. For smaller steps see GB to PB and the TB to GB converter; the Data Units converter covers every unit.
Mistakes to avoid
- Mixing the two systems. 1 TB = 1,000 PB, but 1 TiB = 1,024 PiB. A number counted one way must not be compared with one counted the other.
- Confusing bytes and bits. PB with a capital B is bytes; a lowercase b is bits, an eighth the size.
- Reading a labelled capacity as a binary one. Drive and cloud capacities are sold in SI units, while some operating systems report in binary units under the SI names.
TB to PB Converter FAQ
What is 2500 TB in PB?
2500 TB is 2,500,000 PB in SI counting and 2,560,000 PiB in binary counting.
How many 20 TB drives make a petabyte?
In SI counting 1 PB is 1,000 TB, so it takes 50 drives of 20 TB. Real arrays need extra drives for redundancy and spares, so the raw drive count is higher than the usable petabytes.
Is the answer exact?
Yes. The input is read as an exact decimal and the factors are whole numbers, so every digit shown is correct; only the last shown place is rounded.
References
- NIST, Prefixes for binary multiples
- BIPM, The International System of Units (SI Brochure)
Cite this converter and page
If you use this page in your work, you can cite it as:
Reeliy Editorial Team. (2026). TB to PB Converter. Reeliy. https://reeliy.com/converters/convert-tb-to-pb“TB to PB Converter.” Reeliy, 2026, https://reeliy.com/converters/convert-tb-to-pb.