PB to TB Converter
Type a size in petabytes and read it in terabytes. The box counts 1,000 TB to the petabyte; clear the SI box to count 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.
TB = PB ÷ 1,000 (SI)
TiB = PiB ÷ 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 PiB and TiB, so you can tell which system an answer belongs to.
Where PB to TB comes up
Petabytes are the unit of data centres, research archives and cloud storage fleets; terabytes are the unit of the individual drives and volumes inside them. Going from PB to TB tells you how many 1 TB-class disks, or how many 20 TB drives, a pool represents, and lets you compare a vendor's petabyte figure with the terabyte quota on a storage plan.
How to convert PB to TB
- Type the number of petabytes in the first box.
- Leave Use SI standard ticked for thousands, or clear it for 1,024s.
- The TeraBytes 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: 3.5 PB
Take 3.5 PB. In SI counting that is 3.5 ÷ 1,000 = 0.0035 TB. In binary counting it is 3.5 ÷ 1,024 = 0.00341797 TiB, using PiB and TiB.
PB to TB table
| PetaBytes (PB) | TB, SI (÷ 1,000) | TiB, binary (÷ 1,024) |
|---|---|---|
| 1 | 0.001 | 0.000976563 |
| 2 | 0.002 | 0.00195313 |
| 5 | 0.005 | 0.00488281 |
| 10 | 0.01 | 0.00976563 |
| 25 | 0.025 | 0.0244141 |
| 50 | 0.05 | 0.0488281 |
| 100 | 0.1 | 0.0976563 |
| 500 | 0.5 | 0.4883 |
| 1,000 | 1 | 0.9766 |
For the opposite step use the TB to PB converter. To go further down, see PB to GB and PB to MB; for one step up, PB to EB. The Data Units converter handles every unit from bits to exabytes.
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.
PB to TB Converter FAQ
What is 3.5 PB in TB?
3.5 PB is 0.0035 TB in SI counting and 0.00341797 TiB in binary counting.
Why does a 1 PB array hold less than 1,000 TB in the operating system?
Because the array is sold in SI units (1 PB = 1015 bytes) while some systems report in binary units: 1015 bytes is about 909.5 TiB. Nothing is missing; the unit changed. Clear the SI box to see the binary figures.
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). PB to TB Converter. Reeliy. https://reeliy.com/converters/convert-pb-to-tb“PB to TB Converter.” Reeliy, 2026, https://reeliy.com/converters/convert-pb-to-tb.