How many gigabytes are in a petabyte?

Using the SI decimal standard: 1 PB = 1,000,000 GB. Using the IEC binary standard: 1 PiB (pebibyte) = 1,048,576 GiB (gibibytes). Storage manufacturers use PB; most operating systems use PiB but often label them "PB."

Why is 1,000,000 GB not exactly 1 PB on my operating system?

The OS reports sizes in pebibytes (powers of 1,024), while vendors rate capacity in SI petabytes (powers of 1,000). Since 1 PiB = 1,048,576 GiB vs 1 PB = 1,000,000 GB, the same byte count results in a smaller number when expressed in PiB, creating the apparent discrepancy.

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 gigabytes to petabytes?

Divide the gigabyte value by 1,000,000 to get SI petabytes (PB). Divide gibibytes by 1,048,576 to get binary pebibytes (PiB). For hardware and cloud storage, dividing by 1,000,000 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 gigabytes, the result is accurate to the display precision shown.

Gigabytes to Petabytes Converter

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

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

Input — Gigabytes

Number of gigabytes

SI vs. binary: 1 PB (petabyte, decimal) = 1,000,000 GB. 1 PiB (pebibyte, binary) = 1,048,576 GiB. Storage vendors use PB; your OS reports PiB (but often labels them "PB").

Results

Enter a gigabyte value and click Convert.

Reference Table — Common Gigabyte Counts

Quick lookup for typical data center and cloud storage sizes.

Gigabytes (GB)	PB (SI, ÷1,000,000)	PiB (binary, ÷1,048,576)	Typical example

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Summary

Enter a gigabyte 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 gigabytes in the input field.
The tool divides by 1,000,000 to get decimal petabytes (PB, SI).
It also divides by 1,048,576 to get binary pebibytes (PiB, IEC), treating the input as gibibytes.
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 gigabyte counts in PB and PiB.

Use cases

Estimate how many petabytes a large data set occupies when its size is reported in gigabytes.
Understand cloud storage bills that charge per petabyte when capacity is measured in gigabytes.
Convert data center inventory counts from gigabytes 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