G25 distance calculator

The calculation is Euclidean distance across all 25 dimensions: for each dimension, take the difference between your value and the reference population's, square it, add the 25 squares together and take the square root. Every population in the era you pick is scored that way and the list is sorted, closest first. There is no weighting, no model and nothing fitted — it is one arithmetic operation repeated across the panel, which is why it returns instantly and why the same input always gives the same ranking.

Era matters more than most people expect. A reference panel scoped to the Late Bronze Age and one scoped to the Modern Era contain different populations, so 'closest' means something different in each — being nearest to a modern national average says where you sit among people alive today, while being nearest to an Iron Age group says where you sit among the samples excavated from that window. Comparing across eras is the interesting part; treating one era's ranking as the answer is the common mistake.

What a small distance is not. It is not a measure of descent, and it is not a family connection: a population can sit close to you because you genuinely share ancestry with it, or because it is itself a mixture that happens to average out near your point. Reference populations are averages of individuals, so matching an average closely is not the same as matching anyone who lived — and two populations only a little further down the list are often statistically indistinguishable from the top one. Rank order is not significance, and a distance-based ranking cannot reject anything. If you need a method that can test a model and refuse it, that is qpAdm.

Everything runs in your browser: the coordinate you paste is not uploaded and nothing is stored. The reference panels are the same curated ones the paid Global25 report is computed against — the era populations are public, read-only data.