What is a nonillion?

A nonillion is the number 1,000,000,000,000,000,000,000,000,000,000 — a one followed by thirty zeros. It equals one thousand octillions. Nonillion-scale numbers are found in theoretical mathematics, quantum mechanics, and information theory, where the total number of possible states in a complex system can reach this magnitude. For perspective, certain estimates of the total number of particles in the observable universe fall within the nonillion range.

Thirty zeros are completely impractical to count or type by hand. Even displaying a nonillion on a single line requires careful formatting. A dedicated converter makes it possible to go from the compact "nonillion" notation to the full digit string — and back — without error.

Tool description

This tool converts numbers expressed in nonillions to their full numeric form and vice versa. Enter a value in the "Nonillions" field to see it expanded with all thirty zeros, or input a massive number in the "Full Number" field to find how many nonillions it contains. The conversion is bidirectional and happens instantly.

Examples

Nonillions Full Number
1 1000000000000000000000000000000
5 5000000000000000000000000000000
0.5 500000000000000000000000000000
2.7 2700000000000000000000000000000
0.001 1000000000000000000000000000

Features

  • Instant bidirectional conversion between nonillions and full numbers
  • String-based decimal shifting handles 30+ digit numbers with zero precision loss
  • Accurate decimal support (e.g. 1.5 nonillion → correct 31-digit number)
  • Runs entirely client-side with no server dependency
  • One-click swap to reverse the conversion direction

Use cases

  • Expressing theoretical particle counts in physics and cosmology papers
  • Converting large combinatorial or probability figures in mathematics
  • Writing out extreme-scale values for educational and reference materials
  • Octillion Number Converter — for numbers with 27 zeros
  • Decillion Number Converter — for numbers with 33 zeros