How many megabytes are in 1 petabyte (SI)?

In the SI decimal standard, 1 petabyte (PB) equals exactly 1,000,000,000 megabytes (10^9 MB). This is the definition used by cloud storage providers and hard drive manufacturers.

How many mebibytes are in 1 pebibyte (IEC binary)?

In the IEC binary standard, 1 pebibyte (PiB) equals exactly 2^30 mebibytes = 1,073,741,824 MiB. Operating systems such as Linux report storage in binary units, often labeling them "PB" even though the correct term is "PiB".

What is the difference between PB and PiB?

1 PB (petabyte, SI) = 10^15 bytes. 1 PiB (pebibyte, IEC) = 2^50 bytes = 1,125,899,906,842,624 bytes. A pebibyte is about 12.59% larger than a petabyte. When converting to megabytes, 1 PB = 10^9 MB while 1 PiB = 1,073,741,824 MiB.

How do I convert petabytes to megabytes?

Multiply the petabyte value by 1,000,000,000 (10^9) to get SI megabytes. For binary pebibytes, multiply the PiB value by 1,073,741,824 (2^30) to get mebibytes (MiB).

Why does my OS show fewer MB than the SI formula predicts?

Operating systems (Linux, older Windows) traditionally count in binary units. A drive labeled 1 PB (SI = 10^15 bytes) will show as roughly 0.888 PiB — or about 953,674,316 MiB — in binary-based tools. The SI petabyte and the OS's binary reading differ by about 11.2%.

Petabytes to Megabytes Converter

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

Enter a petabyte (or pebibyte) count and instantly get the megabyte (or mebibyte) result, plus all intermediate storage units.

Enter Petabyte Value

Number of Petabytes

Input unit

Results

Enter a value and click Convert to see results.

Bytes (B)

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SI Decimal (powers of 1,000)

Kilobytes (KB)

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Megabytes (MB)

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Gigabytes (GB)

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Terabytes (TB)

—

Petabytes (PB)

—

IEC Binary (powers of 1,024)

Kibibytes (KiB)

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Mebibytes (MiB)

—

Gibibytes (GiB)

—

Tebibytes (TiB)

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Pebibytes (PiB)

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Petabyte to Megabyte Reference

Description	Petabytes (PB)	MB (SI)	MiB (binary)

Click any row to load that value into the converter.

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Summary

Enter a petabyte (or pebibyte) count and instantly get the megabyte (or mebibyte) result, plus all intermediate storage units.

How it works

Enter the number of petabytes (or pebibytes) in the input field.
Select whether your input uses SI decimal (PB) or IEC binary (PiB).
The converter multiplies by 10^15 to get bytes, then divides by 10^6 for the SI megabyte (MB) result.
For binary, it multiplies by 2^50 to get bytes, then divides by 2^20 for the mebibyte (MiB) result.
All intermediate SI units (KB, MB, GB, TB) and IEC units (KiB, MiB, GiB, TiB) appear simultaneously.
Click any row in the reference table to load that petabyte value into the converter.

Use cases

Find how many megabytes fit in a petabyte-scale cloud storage quota.
Convert data warehouse or backup archive sizes from PB to MB for reporting.
Understand the MB equivalent of PiB values reported by Linux storage tools.
Cross-check vendor storage specs listed in PB against application logs in MB.
Plan capacity upgrades by seeing how many MB a fraction of a petabyte represents.

Frequently Asked Questions

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