How Many Zeros in a Petabyte?
By Vinitha Published Updated
How many zeros in a petabyte? A petabyte (PB) has 15 zeros in the decimal system: 1,000,000,000,000,000 bytes, or 1015 bytes. One petabyte equals 1,000 terabytes or one quadrillion bytes. The prefix peta- traces back to the Greek word for five, reflecting its position as the fifth step up the SI storage scale from a single byte. For more on the 2022 SI prefix additions, see how many zeros in a quettabyte.
A petabyte has
15
zeros
- Written Form
- 1 followed by 15 zeros bytes
- Scientific
- 10¹⁵ bytes
- Binary (IEC)
- 2⁵⁰ bytes (PiB)
Verifying the Zero Count in a Petabyte
The direct answer: exactly 15 zeros. This is the same number of zeros as one quadrillion, since a petabyte is literally one quadrillion bytes. The binary equivalent — a pebibyte (PiB) — equals 250 bytes, roughly 12.6% larger. How many zeros does a gigabyte have covers the 10⁹ value alongside decimal versus binary sizes.
| Unit | Bytes | Zeros | Notation |
|---|---|---|---|
| Petabyte (decimal, SI) | 1,000,000,000,000,000 | 15 | 1015 |
| Pebibyte (binary, IEC) | 1,125,899,906,842,624 | — | 250 |
What Can You Store in a Petabyte?
- Roughly 13 years of continuous HD video streaming
- About 200 million high-resolution photos (at 5 MB each)
- Approximately 500 million pages of plain text
Facebook processes several petabytes of new data every day, and the Large Hadron Collider at CERN generates around 15 petabytes of data annually from its particle collision experiments.
Who Actually Uses a Petabyte?
- Large cloud providers and hyperscale data centers
- Scientific research institutions (particle physics, genomics)
- National archives and large-scale video streaming platforms
How Does a Petabyte Compare to a Terabyte?
One petabyte equals exactly 1,000 terabytes. Since a modern consumer hard drive holds 1–4 TB, a single petabyte would require hundreds of such drives. Zeros in a gigabit covers Gbps and Mbps in network speeds alongside eight binary digits in each unit of storage.
| Unit | Zeros | Bytes | Equivalent |
|---|---|---|---|
| Gigabyte (GB) | 9 | 109 | 1,000 MB |
| Terabyte (TB) | 12 | 1012 | 1,000 GB |
| Petabyte (PB) | 15 | 1015 | 1,000 TB |
| Exabyte (EB) | 18 | 1018 | 1,000 PB |
Watch: How Many Zeros in a Petabyte?
How many zeros in a petabyte? A petabyte has 15 zeros — 1 followed by 15 zeros bytes. Watch this short video for the zero count, the written form and the notation at a glance.
Zeros in a Petabyte: FAQ
What comes before a petabyte?
Quick answer
Terabyte comes right before petabyte — a petabyte is exactly 1,000 terabytes.
What comes after a petabyte?
Quick answer
Exabyte comes next, followed by zettabyte.
How many digits does a petabyte have?
A petabyte has 16 digits in total — that's the digit 1 followed by 15 zeros.
Is a petabyte the same as a quadrillion bytes?
Yes — a decimal petabyte (1015 bytes) is exactly one quadrillion bytes.
Who actually uses petabyte-scale storage?
Large enterprises, cloud providers, and research institutions — petabyte scale is well beyond typical consumer or small-business storage needs.
How many petabytes are in an exabyte?
Exactly 1,000 petabytes make one exabyte.
About the Author
Designer and Developer · Palakkad, Kerala, India
Vinitha holds a bachelor's degree in Textile and Apparel Design from Avinashilingam University, plus a C-Tech certificate in Graphic Design from Image Creative Education. She builds free, no-clutter reference tools like How Many Zeros. Read her full bio.