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Loan Calculator — Compare EMI at Three Tenures Side by Side

Educational content only — not financial advice

A ₹50 lakh home loan at 9% over 20 years has an EMI of about ₹44,986 and total interest of about ₹57.97 lakh. The same loan stretched to 30 years drops the EMI to about ₹40,231 — a ₹4,755 monthly relief — but the total interest paid balloons to about ₹94.83 lakh. Same loan, same rate, ₹37 lakh more paid out, just for the longer cushion. The trade-off between cash-flow comfort and total cost is the single most expensive decision most borrowers make and the one most rarely quantified before signing. Pick a loan type below to see your own numbers across three tenures at once.

Indian credit-card APRs run 36–42%; personal loans 10.5–24%; home loans 8.5–10% (late 2024). U.S. credit cards average ~22%; personal loans 7–36%; mortgages 6.5–7.5%.

2 years

Monthly EMI

₹24,006

Total interest
₹76,155
Total amount paid
₹5,76,155

3 years

Monthly EMI

₹17,089

Total interest
₹1,15,197
Total amount paid
₹6,15,197

5 years

Monthly EMI

₹11,634

Total interest
₹1,98,048
Total amount paid
₹6,98,048

Compare the same loan at three tenures to see the trade-off directly: a longer tenure cuts the monthly EMI but increases total interest over the life of the loan, often by a multiple. The right tenure depends on cash-flow tolerance more than on the rate itself.

The math behind the calculator

Every amortising loan — home loan, auto loan, personal loan, education loan, or a credit-card balance treated as one — uses the same EMI formula:

EMI = P × i × (1+i)^n / ((1+i)^n − 1)
  • P is the principal — the loan amount.
  • i is the monthly interest rate (annual rate ÷ 12, expressed as a decimal — so 12% APR becomes 0.01).
  • n is the number of months over which the loan is repaid.

Multiply the EMI by n to get the total amount paid across the life of the loan; subtract the principal to get the total interest paid. The interest portion is dominant in the early months of any long-tenure loan because the outstanding balance is at its highest — which is why front-loaded prepayments save the most.

A worked example — the 15 vs 30 year mortgage trap

A $300,000 mortgage at 7% APR over two tenures, run through the calculator:

| Tenure | Monthly EMI | Total interest | Total paid | |---|---:|---:|---:| | 15 years (180 months) | $2,696 | $185,367 | $485,367 | | 30 years (360 months) | $1,996 | $418,527 | $718,527 |

The 30-year mortgage saves $700 per month in cash flow but costs an extra $233,160 in interest over the life of the loan. The 15-year loan pays the same property off in half the time at less than half the total interest cost — but only works for households whose monthly cash flow can absorb the higher EMI without breaking other categories.

The same pattern shows up at every loan size: a ₹15 lakh personal loan at 12% is ₹33,367/month over 5 years (₹5.02 lakh interest) versus ₹21,494/month over 10 years (₹10.79 lakh interest) — half the monthly relief, more than double the interest cost.

Pair this calculator with the explainers

For the broader concept of how interest works on debt, see What Is an Interest Rate Explained. For the credit-card-specific application — daily compounding, minimum payment trap, average daily balance — see How Does Credit Card Interest Work. For modelling how long a credit-card balance takes to pay off, see How Long Does It Take to Pay Off Credit Card Debt. For the two main payoff strategies when juggling multiple debts, see How the Debt Snowball Method Works and How the Debt Avalanche Method Works. For the consolidation alternative, see What Is a Debt Consolidation Loan.

Most borrowers anchor on the EMI alone and never compute the total interest at the alternative tenures available to them. The trade-off becomes obvious once you can see all three tenures side by side — and the right answer is rarely the longest-possible tenure even when it produces the most comfortable monthly payment.

Frequently asked questions

What does the calculator actually compute?

It calculates the monthly EMI (equated monthly instalment) for an amortising loan using the standard formula EMI = P × i × (1+i)^n / ((1+i)^n − 1), where P is the principal, i is the monthly interest rate, and n is the tenure in months. It then multiplies EMI by the number of months to get the total amount paid over the loan, and subtracts the principal to get the total interest paid. Three tenures run side by side so the rate-vs-tenure trade-off is visible at a glance.

Why is the total interest so much larger at a longer tenure?

Each EMI on a longer tenure pays down a smaller share of the principal in the early months, so the outstanding balance — which interest is calculated on — stays high for longer. Doubling the tenure usually less than halves the EMI, but it can more than double the total interest paid. A ₹50 lakh / $300,000 home loan at 9% over 30 years versus 15 years is roughly the same EMI ratio (about 1.4×) but the 30-year loan pays roughly 2.4× the total interest of the 15-year loan.

Which interest rate should I use?

Use the actual rate the lender quoted, not a benchmark or repo rate. As of late 2024, Indian credit card APRs run 36–42% on outstanding balances, personal loans 10.5–24%, and home loans 8.5–10% (SBI/HDFC/ICICI). U.S. credit card APRs average ~22% (Federal Reserve G.19), personal loan APRs span 7–36% by credit profile, and 30-year fixed mortgages run 6.5–7.5%. For a planning estimate, use the median of the typical range for your loan type.

How accurate is the EMI for credit-card debt?

It models a credit-card payoff if you commit to a fixed monthly payment, like a personal loan. Actual credit cards charge interest daily on the average daily balance and don't enforce a fixed payoff schedule — the calculator's output is the discipline target, not the literal mechanic. Treating credit-card debt as a fixed-EMI loan you pay yourself is one of the cleanest ways to escape the minimum-payment trap, and the calculator quantifies what payment to commit to.

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