How many terabytes are in a petabyte?

Using the SI decimal standard: 1 PB = 1,000 TB. Using the IEC binary standard: 1 PiB (pebibyte) = 1,024 TiB (tebibytes). Storage manufacturers use PB; most operating systems report in PiB but often label them "PB."

Why does my OS show a different petabyte count than the vendor spec?

Operating systems display sizes in pebibytes (powers of 1,024), while vendors rate capacity in SI petabytes (powers of 1,000). Since 1 PiB = 1,024 TiB and 1 PB = 1,000 TB, the same byte count results in a slightly different number depending on which standard is used.

What is the difference between PB and PiB?

PB (petabyte) follows the SI decimal system: 1 PB = 1,000 TB = 1,000,000,000,000,000 bytes. PiB (pebibyte) follows the IEC binary system: 1 PiB = 1,024 TiB = 1,125,899,906,842,624 bytes. 1 PiB is about 12.6% larger than 1 PB.

How do I convert terabytes to petabytes?

Divide the terabyte value by 1,000 to get SI petabytes (PB). Divide tebibytes by 1,024 to get binary pebibytes (PiB). For hardware and cloud storage, dividing by 1,000 matches what vendors advertise.

How accurate is this converter for very large values?

The converter uses JavaScript 64-bit floating-point (IEEE 754 double precision), which handles integers exactly up to 2^53. For any practical storage size in terabytes, the result is accurate to the display precision shown.

Terabytes to Petabytes Converter

Name: Terabytes to Petabytes Converter
Availability: InStock
Author: Nham Vu

Enter a terabyte value and instantly get petabytes (PB, decimal SI) and pebibytes (PiB, binary IEC), plus a quick-reference table.

Input — Terabytes

Number of terabytes

SI vs. binary: 1 PB (petabyte, decimal) = 1,000 TB. 1 PiB (pebibyte, binary) = 1,024 TiB. Storage vendors use PB; your OS reports PiB (but often labels them “PB”).

Results

Enter a terabyte value and click Convert.

Reference Table — Common Terabyte Counts

Quick lookup for typical data center and cloud storage sizes.

Terabytes (TB)	PB (SI, ÷1,000)	PiB (binary, ÷1,024)	Typical example

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Summary

Enter a terabyte value and instantly get petabytes (PB, decimal SI) and pebibytes (PiB, binary IEC), plus a quick-reference table.

How it works

Enter the number of terabytes in the input field.
The tool divides by 1,000 to get decimal petabytes (PB, SI).
It also divides by 1,024 to get binary pebibytes (PiB, IEC), treating the input as tebibytes.
Results appear instantly with up to 10 significant digits.
Use the copy buttons to grab any result value.
Scroll down for a reference table of common terabyte counts in PB and PiB.

Use cases

Estimate how many petabytes a large data set occupies when its size is quoted in terabytes.
Understand cloud storage bills that charge per petabyte when disk capacity is measured in terabytes.
Convert data center inventory from terabytes to petabytes for executive reporting.
Translate backup or archive sizes into petabytes for long-term capacity planning.
Cross-reference OS-reported sizes (PiB) against hardware specs (PB) at scale.
Verify storage estimates when migrating large databases or object stores.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu