How it works
Every EMI is the same size, but its composition changes completely over the life of the loan. On a twenty-year home loan at 8.5%, the first instalment is about 87% interest and 13% principal. Only around year twelve does principal overtake interest. That is why the outstanding balance barely moves in the early years, and why prepaying early is worth so much more than prepaying late.
The total interest is the number worth looking at, and it is rarely quoted. A ₹30 lakh loan at 8.5% over twenty years costs about ₹32.5 lakh in interest — more than the amount borrowed. Cutting the tenure to fifteen years raises the EMI by roughly ₹3,500 but saves close to ₹9 lakh.
EMI = P x i x (1+i)^n ÷ ((1+i)^n − 1)
- P is the loan principal
- i is the monthly interest rate — the annual rate divided by twelve
- n is the number of monthly instalments
- Each instalment is split into interest on the opening balance and principal, which is the remainder
- Check the total interest, not just the EMIA longer tenure lowers the monthly payment and raises the lifetime cost, often dramatically.
- Keep the EMI within about 40% of take-homeLenders will approve more. Beyond 40%, one income disruption turns a manageable loan into a default.
- Prepay early or not at allA prepayment in year three removes far more interest than the same amount in year fifteen, because it cancels interest on every remaining month.
- Prefer a shorter tenure to a bigger loanIf the EMI is affordable, fifteen years beats twenty. If it is not, the loan is too large.
- Watch for floating-rate resetsMost Indian home loans are linked to the repo rate. A rate rise usually extends the tenure silently rather than raising the EMI.
A worked example
The EMI is about ₹26,035. Over 240 instalments you pay ₹62,48,000 in total, of which ₹32,48,000 is interest — more than the ₹30,00,000 you borrowed. In the first year, roughly ₹2,53,000 of your ₹3,12,000 in payments goes to interest and only ₹59,000 reduces the balance.
Paying an extra ₹5,000 a month changes the picture sharply: the loan clears in about sixteen years instead of twenty and total interest falls by roughly ₹7,60,000. That is a return no fixed-income investment will match after tax.
Common mistakes
- Choosing the longest tenure to get the lowest EMI, then paying lakhs more in interest
- Borrowing the full amount a lender approves rather than the amount the budget supports
- Ignoring processing fees, insurance and stamp duty, which add 1–2% to the real cost
- Prepaying in the final years, when almost all the interest has already been charged
- Missing that a floating-rate rise silently lengthens the tenure instead of raising the EMI
Tenure against total cost (₹30 lakh at 8.5%)
| Tenure | EMI | Total interest | Total paid |
|---|---|---|---|
| 10 years | ₹37,195 | ₹14,63,000 | ₹44,63,000 |
| 15 years | ₹29,542 | ₹23,18,000 | ₹53,18,000 |
| 20 years | ₹26,035 | ₹32,48,000 | ₹62,48,000 |
| 25 years | ₹24,159 | ₹42,48,000 | ₹72,48,000 |
| 30 years | ₹23,067 | ₹53,04,000 | ₹83,04,000 |
Frequently asked questions
EMI = P × i × (1+i)^n ÷ ((1+i)^n − 1), where P is the principal, i the monthly rate and n the number of instalments. Each payment covers interest on the outstanding balance first, and whatever remains reduces the principal.
Related calculators
Related terms
Related guides
How BudgetAnalyzer helps
An EMI is the largest fixed line in most budgets, and it needs to be visible next to everything else. BudgetAnalyzer tracks loan repayments alongside your other spending and keeps outstanding balances in Lend & Borrow, so your net worth reflects what you owe as well as what you own.