Going from Persian (Farsi) to Indonesian (Bahasa Indonesia) has a composite linguistic distance of 80% (heuristic estimate). Below is the dimension-by-dimension breakdown.
Shared vocabulary, cognates, and loanwords.
Morphology, syntax, word order, cases.
Shared sounds and phoneme inventory.
Arabic → Latin
Indo-European ↔ Austronesian
The 5 languages with the lowest linguistic distance from Persian (Farsi):
A quick 3-question check between Persian (Farsi) and Indonesian. No signup.