Archive / Investment Adviser (Level 1) / Debt Management and Loans

nism-series-xa-home-loan-emi-interest-principal-schedule[ INVESTMENT ADVISER (LEVEL 1) ]

In a standard 20-year fixed-installment Home Loan amortization schedule, how does the proportion of Interest (IPMT) versus Principal (PPMT) evolve over time?

[ A ]Interest forms the dominant majority of EMI in the early years and declines progressively, while principal repayment starts low and increases exponentially in later years.[ CORRECT ]

[ B ]Every single monthly EMI contains exactly 50% interest and 50% principal across all 240 months.

[ C ]Interest is paid as a single lump sum at the end of Year 20.

[ D ]Principal repayment forms 90% of EMI in Year 1 and decreases to 10% in Year 20.

Takeaway

In a reducing-balance EMI schedule, interest dominates the EMI in the early years (when outstanding principal is highest) and steadily gives way to principal repayment as the loan matures.

Derivation

Each EMI = fixed IPMT + PPMT, where IPMT for a given month is calculated as the prevailing outstanding principal x the periodic interest rate. In Month 1 of a 20-year loan, outstanding principal is at its maximum, so IPMT consumes the largest share of the EMI while PPMT is small. As each month's PPMT chips away at the balance, the base on which interest is charged shrinks, so IPMT falls and PPMT rises every month — accelerating sharply once the balance has been substantially reduced (roughly the back third of the tenure). This is why prepaying a home loan early saves disproportionately more interest than prepaying late, a key financial-planning takeaway tested here.

Why the others fail

B — Every single monthly EMI contains exactly 50% interest and 50% principal across all 240 months.

A constant 50:50 split across all 240 months would require interest to remain flat even as the outstanding principal declines monthly — mathematically inconsistent with reducing-balance interest.

C — Interest is paid as a single lump sum at the end of Year 20.

Interest accrues and is serviced within every monthly EMI throughout the tenure; it is never deferred as a single terminal lump-sum payment under a standard amortizing loan.

D — Principal repayment forms 90% of EMI in Year 1 and decreases to 10% in Year 20.

This describes the opposite of amortization mechanics: outstanding principal — and therefore IPMT's share — is highest in Year 1, not lowest, so principal cannot start at 90%.