How Many Zeros in a Quettabyte?
A quettabyte (QB) has 30 zeros: 1,000,000,000,000,000,000,000,000,000,000 bytes, or 1030 bytes. One quettabyte equals 1,000 ronnabytes or one nonillion bytes. The quettabyte is the largest officially recognized SI storage unit as of today. It was added to the international metric system in November 2022 by the BIPM — the same update that introduced the ronnabyte (1027). The prefix "quetta-" was coined specifically to fill this position, with the letter Q chosen to avoid overlap with any existing unit symbol. Related: Zeros in a bit.
A quettabyte has
30
zeros
- Written Form
- 1 followed by 30 zeros bytes
- Scientific
- 10³⁰ bytes
How Many Zeros Are in a Quettabyte?
In the decimal system, 1 QB = 1,000,000,000,000,000,000,000,000,000,000 bytes — exactly 30 zeros following the leading 1. The exponent in 1030 states this directly: 30 zeros, equal to one nonillion. Each step up the SI storage ladder adds three zeros, so a quettabyte has three more zeros than a ronnabyte (27 zeros) and six more than a yottabyte (24 zeros). See also: How many zeros does a terabyte have.
| Unit | Zeros | Bytes | Equivalent |
|---|---|---|---|
| Yottabyte (YB) | 24 | 1024 | 1,000 ZB |
| Ronnabyte (RB) | 27 | 1027 | 1,000 YB |
| Quettabyte (QB) | 30 | 1030 | 1,000 RB |
How Big Is a Quettabyte?
A quettabyte defies any practical comparison to everyday storage. The total data generated by all of humanity in a year currently sits in the tens of zettabytes — still nine orders of magnitude smaller than a single quettabyte. To picture the gap: if all the data created globally in a year were a single grain of sand, a quettabyte would be roughly a billion beaches. See also: How many zeros does a gigabyte have.
Even the most ambitious scientific data projects — the Square Kilometre Array radio telescope, which will generate about 700 terabytes per second of raw data — would need hundreds of millions of years of continuous observation to accumulate a single quettabyte. The quettabyte is defined now so the scientific and engineering communities have an official name ready when they eventually need it.
Who Named the Quettabyte?
The quettabyte was proposed by Richard Brown, a metrologist at the UK's National Physical Laboratory, and ratified at the 27th General Conference on Weights and Measures (CGPM) in November 2022. Brown developed the new prefixes after recognizing that global data volumes were advancing toward the yottabyte scale faster than expected, and that informal names like "brontobyte" were being used inconsistently in technical literature.
The naming process for SI prefixes requires international consensus and avoids any letters already claimed by existing units. "Quetta-" (Q) and "ronna-" (R) were both selected on that basis. With quettabyte now officially defined at 1030, the SI system extends far enough to remain useful for decades of data growth.