How Many Zeros in a Quettabyte?
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 — currently the largest officially recognized SI storage unit. See also: Zeros in a gigabyte.
A quettabyte has
30
zeros
- Written Form
- 1 followed by 30 zeros bytes
- Scientific
- 10³⁰ bytes
Quettabyte: The Newest SI Storage Prefix
The direct answer: exactly 30 zeros, equal to one nonillion. It was added to the international metric system in November 2022 by the BIPM — the same update that introduced the ronnabyte. The prefix "quetta-" was coined specifically to fill this position, with the letter Q chosen to avoid overlap with any existing unit symbol.
| 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. See also: How many zeros does a gigabit have.
Why Define a Unit Nobody Needs Yet
- SI prefixes take years to standardize internationally
- Data volumes have historically outpaced existing unit ceilings
- Having the name ready avoids ad hoc, inconsistent terminology later
Even the Square Kilometre Array radio telescope, which generates 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?
- Proposed by
- Richard Brown, metrologist at the UK's National Physical Laboratory
- Ratified
- 27th General Conference on Weights and Measures (CGPM), November 2022
- Symbol chosen
- "Q" — selected to avoid conflict with any existing unit abbreviation
Zeros in a Quettabyte: FAQ
What comes before a quettabyte?
Quick answer
Ronnabyte comes right before quettabyte — a quettabyte is exactly 1,000 ronnabytes.
What comes after a quettabyte?
Quick answer
Nothing yet — the quettabyte is the largest officially recognized SI storage unit as of today. See also: How many zeros in a kilobyte.
How many digits does a quettabyte have?
A quettabyte has 31 digits in total — that's the digit 1 followed by 30 zeros.
Is a quettabyte the same as a nonillion bytes?
Yes — a decimal quettabyte (1030 bytes) is exactly one nonillion bytes.
Does any real system need quettabyte-scale storage?
Not yet — it was defined ahead of need so the naming system stays ready for future data growth.
How many zeros in a quettabyte vs a yottabyte?
A quettabyte has 30 zeros; a yottabyte has 24 — six fewer, a difference of one million.