Prepayment Simulator
Drop a lumpsum or bump your monthly EMI and watch how much interest, and how many months, you cut off your loan.
Almost always, since it reduces the principal your interest is calculated on for every remaining month. The exceptions are loans with prepayment penalties large enough to offset the savings, check your loan agreement.
For the same total amount prepaid, starting earlier and repeating more frequently saves more interest, since it shrinks the principal sooner. Monthly top ups typically save the most; a single early lumpsum is the next best.
Depends on what you tell your lender, most let you choose between a lower EMI (same tenure) or a shorter tenure (same EMI). This simulator models the shorter tenure approach, which usually saves more total interest.