What is the Loan Tenure Reduction Calculator?
This calculator shows how many months (and years) you can cut off a loan by making a one-time lump-sum prepayment while keeping the same monthly EMI. Instead of lowering your installment, the prepayment shortens how long you pay — usually saving a large amount of interest.
How to use it
Enter your current outstanding loan balance, the lump-sum amount you intend to prepay, your fixed monthly EMI, and the annual interest rate. The tool computes the remaining tenure before and after the prepayment and reports the months saved.
The formula explained
The remaining number of months for a loan balance B at monthly rate r with installment EMI is derived from the amortization equation:
$$n = \frac{-\ln\!\left(1 - \dfrac{r\cdot B}{\text{EMI}}\right)}{\ln(1 + r)}$$
where \(r = \text{annual rate} / 100 / 12\). We compute \(n\) for the original balance and for the reduced balance (\(B = \text{outstanding} - \text{prepayment}\)), then subtract: \(\text{monthsSaved} = n_{\text{old}} - n_{\text{new}}\).
Worked example
Outstanding = 500,000; prepayment = 100,000; EMI = 10,000; rate = 9% (\(r = 0.0075\)). Original tenure = $$\frac{-\ln(1 - 0.0075\cdot 500000/10000)}{\ln(1.0075)} = \frac{-\ln(0.625)}{\ln(1.0075)} \approx 62.90 \text{ months.}$$ New balance = 400,000, new tenure = $$\frac{-\ln(1 - 0.0075\cdot 400000/10000)}{\ln(1.0075)} = \frac{-\ln(0.70)}{\ln(1.0075)} \approx 47.73 \text{ months.}$$ Months saved \(\approx 15.17\) (about 1.26 years).
FAQ
Does my EMI change? No. This method keeps the EMI fixed and reduces the loan duration instead.
What if EMI is too low? If the EMI does not exceed the monthly interest on the balance, the loan never amortizes and tenure is undefined; the calculator returns 0 in that edge case.
Is this universal? Yes — it is pure financial math and applies to any fixed-rate, fixed-EMI loan regardless of country.
