Going from Persian (Farsi) to Nepali (เคจเฅเคชเคพเคฒเฅ) has a composite linguistic distance of 75% (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 โ Devanagari
Indo-European โ Indo-European
The 5 languages with the lowest linguistic distance from Persian (Farsi):
A quick 3-question check between Persian (Farsi) and Nepali. No signup.