Methodology. EMI = P×r×(1+r)^n / ((1+r)^n – 1). Tenure-reduction strategy: simulate monthly amortisation, apply lump-sum at month 1, deduct extra EMI each month, count months until balance ≤ 0. EMI-reduction strategy: after lump-sum, recompute EMI for original remaining tenure on the lower balance. Most home-loan banks now waive prepayment charges on floating-rate loans (RBI mandate); fixed-rate loans may still charge 2-4%. Always confirm prepayment terms with your bank.