Global25 admixture calculator

A Global25 coordinate is 25 numbers that locate one genome in a genetic reference space built from ancient and modern samples. This tool treats your row as a point in that space and searches for the weighted mixture of reference populations whose combined point sits closest to it. The search is a Monte-Carlo fit in the nMonte tradition: it distributes weight across the sources in the calculator you pick, keeps the combinations that reduce the gap, and reports the leftover gap as a fit distance. A smaller fit distance means the mixture lands nearer your coordinate — nothing more than that.

You choose the source panel, and that choice does more to shape the answer than the arithmetic does. A curated calculator is a deliberate, era-scoped set of sources; you can also paste your own. The tool ranks your closest single populations by plain Euclidean distance across all 25 dimensions, so you can see which sources are near you before you ask for a mixture of them. Everything runs in your browser — coordinates you paste are not uploaded, and nothing is stored on our servers.

What it cannot do: a coordinate fit has no p-value and cannot reject a model. It will always return percentages, including from a source panel that contains nobody your ancestors ever met — the fit distance is the only signal that the answer is poor, and a plausible-looking breakdown from a badly chosen panel is the most common way to read a real number wrongly. It also cannot distinguish two source populations that sit close together in the reference space; their weights trade off almost freely. For a method that can test a model and refuse it, see our qpAdm analysis, which works from allele-frequency statistics rather than coordinate distances.