Avortas uses a statistical approach based on trait frequency data from authoritative sources including the World Health Organization (WHO), United Nations demographic data, peer-reviewed studies, and national statistics agencies from 50+ countries. Each trait we track — eye color, hair color, blood type, height, handedness, zodiac sign, and more — has an estimated global frequency expressed as a percentage.
For independent traits, we multiply individual probabilities. For traits that are known to be correlated (such as hair color and eye color in European populations), we use conditional probability estimates from published research to provide more accurate results. The final "rarity score" represents the estimated fraction of the world population that shares your exact trait combination, translated into a "1 in X" figure for easy understanding.
Important limitations: our model treats most traits as globally distributed, but real populations are geographically clustered. A trait combination that is extremely rare globally might be less rare in a specific region. That is why we also offer country-specific rarity calculations for 50 nations, using local demographic data when available. All calculations happen entirely in your browser — no personal data is ever sent to our servers.