A while back I wrote a small package in Javascript for computing area proportional Venn and Euler diagrams: https://github.com/benfred/venn.js . The 2 circle case here is relatively easy, but the problem gets tricky when you have 3+ sets. I wrote up my approach here https://www.benfrederickson.com/venn-diagrams-with-d3.js/ and https://www.benfrederickson.com/better-venn-diagrams/