How Many Zeros in a Ronnabyte?
A ronnabyte (RB) has 27 zeros: 1,000,000,000,000,000,000,000,000,000 bytes, or 1027 bytes. One ronnabyte equals 1,000 yottabytes or one octillion bytes. The ronnabyte was formally adopted by the International Bureau of Weights and Measures (BIPM) in November 2022 as an official SI prefix — the first new storage prefix added since the yottabyte in 1991. The prefix "ronna-" was coined by British metrologist Richard Brown, partly inspired by the Greek "ennea" (nine), since ronnabyte represents the ninth SI storage step above a single byte. See also: Zeros in an exabyte.
A ronnabyte has
27
zeros
- Written Form
- 1 followed by 27 zeros bytes
- Scientific
- 10²⁷ bytes
How Many Zeros Are in a Ronnabyte?
In the decimal system, 1 RB = 1,000,000,000,000,000,000,000,000,000 bytes — exactly 27 zeros following the leading 1. The exponent in 1027 tells you this directly: 27 zeros, equal to one octillion. That is three more zeros than a yottabyte (24 zeros), since each step up the SI storage scale adds exactly three zeros. See also: How many zeros in a gigabit.
| 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 Ronnabyte?
A ronnabyte is so large that no existing technology comes remotely close to storing one. The total amount of data generated globally each year — across all devices, data centers, and internet traffic — is estimated in the tens of zettabytes. That is still three orders of magnitude below a single yottabyte, and six orders of magnitude below a single ronnabyte. See also: Gigabyte zeros.
The ronnabyte exists not because we need it today, but because data volumes are growing exponentially and SI units must be defined well before they are needed in practice. Scientists working with global-scale simulations, astronomical data archives, and climate modeling datasets are among the first to push toward the upper reaches of the petabyte and exabyte scale — still far from the ronnabyte range.
Why Was the Ronnabyte Added to the SI System?
Before 2022, the largest official SI storage prefix was the yottabyte (1024). As global data volumes accelerated toward the yottabyte scale, metrologists recognized that informal and inconsistent terms — like "brontobyte" — were already appearing in technical literature. The BIPM stepped in to standardize two new prefixes at once: ronna- (1027) and quetta- (1030). Both were proposed by Richard Brown of the UK's National Physical Laboratory and ratified at the 27th General Conference on Weights and Measures. The "R" symbol for ronnabyte was chosen specifically to avoid conflict with any existing unit abbreviations.