Etymologikon:

This chart shows the lexical distance — that is, the degree of overall vocabulary divergence — among the major languages of Europe.

The size of each circle represents the number of speakers for that language. Circles of the same color belong to the same language group. All the groups except for Finno-Ugric (in yellow) are in turn members of the Indo-European language family. …

The original research data for the chart comes from K. Tyshchenko (1999), Metatheory of Linguistics. (Published in Russian.)