Loan Prepayment Calculator India — Interest Savings from Part-Payment
When you receive a bonus of ₹3 lakhs, the question is not whether to save it but where it does the most work. Prepaying a ₹30 lakh home loan at 8.5% in Year 3 with that ₹3 lakhs saves approximately ₹5.4 lakh in total interest and cuts over 20 months off the tenure — a guaranteed, risk-free return equivalent to 8.5% on the prepaid amount. An equity mutual fund might return more over a decade, but prepayment returns are certain while investment returns are not. For borrowers who value certainty, prepayment is often the optimal use of a windfall, particularly early in the loan when the principal-to-interest ratio is most unfavourable.
The regulatory context matters critically here. The RBI (Pre-payment Charges on Loans) Directions, 2025 prohibit banks and lending institutions from levying any prepayment or foreclosure charges on floating-rate loans to individual borrowers for non-business purposes — covering home loans, personal loans, car loans, and education loans, with no minimum lock-in and no restriction on amount or source of funds. From 1 January 2026, this protection also extends to floating-rate business loans taken by individuals and MSEs (for loans sanctioned or renewed on or after that date). Fixed-rate loans are not covered — lenders may still charge foreclosure fees on fixed-rate loans if these are board-approved and disclosed upfront. Before prepaying, check your sanction letter: a floating-rate loan references EBLR, MCLR, or Base Rate as the benchmark; a fixed-rate loan states a fixed percentage with no benchmark link. Use the Home Loan EMI Calculator to confirm your current EMI and outstanding balance, and the Loan Eligibility Calculator if you plan to take a fresh loan after prepaying.
How the Loan Prepayment Calculator India Works
Interest saved by prepaying ₹3L on a ₹30L home loan at 8.5% — timing comparison
| Prepayment in Year | Interest Saved (₹) | Months Saved | Equivalent Return |
|---|---|---|---|
| Year 1 | ₹8,40,000 (approx) | ~48 months | ~8.5% guaranteed |
| Year 3 | ₹7,93,000 (approx) | ~42 months | ~8.5% guaranteed |
| Year 5 | ₹7,10,000 (approx) | ~35 months | ~8.5% guaranteed |
| Year 10 | ₹4,60,000 (approx) | ~20 months | ~8.5% guaranteed |
| Year 15 | ₹1,80,000 (approx) | ~7 months | ~8.5% guaranteed |
How Loan Prepayment Saves Interest — Amortisation, Principal Timing, and Why Early Prepayment Wins
In a reducing-balance loan, every EMI has two components: an interest charge on the outstanding principal, and a principal repayment. The split is unfavourable at the start: in a ₹30L home loan at 8.5% for 20 years, Month 1's EMI of ₹26,034 is split as ₹17,750 interest and only ₹8,284 principal. By Month 180 (Year 15), the split reverses: ₹6,100 interest and ₹19,934 principal. The bank collects most of its interest upfront.
A prepayment directly reduces the outstanding principal. Because interest in every subsequent month is charged on that now-smaller balance, the compounding savings are immediate. A ₹3L prepayment in Year 3 does not just save one month's interest on ₹3L — it saves 8.5% annually on ₹3L for each of the remaining approximately 17 years of the loan, compounded through the amortisation schedule. This is why early prepayment saves dramatically more than late prepayment on the same amount.
The two choices after prepayment: When you make a lump sum payment, your lender typically offers: (a) keep the EMI the same and shorten the tenure, or (b) keep the tenure the same and reduce the EMI. Option (a) saves more total interest — because more principal is retired faster and the loan ends sooner. Option (b) is preferred when you need cash flow relief. Most financial planners recommend option (a): keep the EMI constant, cut the tenure, save more interest.
Worked example — ₹30L at 8.5% for 20 years, prepay ₹3L in Year 3: Original EMI: ₹26,034. After 36 EMIs, outstanding principal ≈ ₹28.05L. After prepaying ₹3L: balance ₹25.05L. Keeping EMI at ₹26,034, new tenure ≈ 162 months (previously 204 remaining) — saving 42 months and approximately ₹7.93L in total interest. The ₹3L prepayment generates ₹7.93L in interest savings — a 164% return on the prepaid amount, equivalent to earning 8.5% guaranteed on that ₹3L for the remaining loan period.
Three Prepayment Decisions — Bonus Deployment, Optimal Loan Sequence, and the Invest-vs-Prepay Calculation
Scenario 1: Geeta, 36, ₹3L Diwali bonus — prepay floating-rate home loan or invest in equity mutual fund?
Geeta has a ₹30L home loan at 8.5% (floating rate, 17 years remaining). She receives a ₹3L performance bonus. Two options:
Prepay the home loan: Saves approximately ₹7.93L in total future interest (as calculated above). This is a guaranteed, risk-free return equivalent to 8.5% post-tax — because the interest saved is in post-tax money (home loan interest deduction under Section 24(b) applies only if Geeta is in the old tax regime; if she's in the new regime, there's no deduction and the comparison is even simpler). No market risk, no uncertainty.
Invest in equity mutual fund: At 12% CAGR over 17 years: ₹3L grows to approximately ₹19.4L. Expected returns: significantly higher than ₹7.93L in interest savings. But: equity returns are not guaranteed, carry volatility, and the post-tax CAGR after LTCG (12.5% above ₹1.25L per FY under Section 112A) is approximately 10.5–11%.
The mathematical verdict: at 12% expected equity return (post-tax ≈ 10.5%), equity wins over 17 years on expected value. But the guarantee of 8.5% vs the uncertainty of 10.5% is a risk-preference question. For a borrower who would lie awake worrying about an equity correction, prepayment provides psychological stability worth the expected return gap. For a borrower comfortable with 17-year equity volatility, investing is mathematically better on expected value.
Scenario 2: Sanjay, 41, ₹5L from share sale — three loans, optimal prepayment sequence
Sanjay has three active loans: home loan ₹22L outstanding at 8.5% (floating), car loan ₹3.5L at 10.5% (floating), personal loan ₹1.2L at 16% (fixed, 18 months remaining). He has ₹5L to deploy.
Optimal prepayment sequence: highest effective interest rate first.
- Clear personal loan ₹1.2L first (16% guaranteed return on ₹1.2L, no prepayment penalty since most fixed personal loans allow part-prepayment — verify). Remaining: ₹3.8L.
- Clear car loan ₹3.5L next (10.5% guaranteed return, floating so RBI prohibits foreclosure charges). Remaining: ₹0.3L.
- Put ₹0.3L on home loan (8.5% return).
Result: Sanjay is fully debt-free on personal and car loans, reducing total monthly EMI obligations by approximately ₹22,000/month from next month. This frees cash flow that can then be directed to accelerate the home loan repayment or to investments.
Scenario 3: Lalitha, 43, fixed-rate loan — checking whether the foreclosure charge erases the benefit
Lalitha has a fixed-rate home loan: ₹15L outstanding at 9% fixed, 10 years remaining. She has ₹5L to prepay. Her bank charges a 2% foreclosure fee on the prepaid amount: 2% × ₹5L = ₹10,000.
Interest saved by prepaying ₹5L now at 8.5% for 10 remaining years: approximately ₹3.8L. Cost of prepayment: ₹10,000 penalty. Net saving: ₹3.79L — the 2% penalty barely dents the benefit. Lalitha should prepay. The penalty only becomes a significant drag if the loan tenure remaining is very short (2–3 years) — then the interest saved may be smaller and the penalty a larger fraction of the benefit. Use this calculator to model the specific saving, then compare against your fixed-rate penalty amount before deciding.
RBI (Pre-payment Charges on Loans) Directions, 2025 — What the Rule Covers, What It Doesn't, and the Tax Angle on Home Loan Prepayment
RBI (Pre-payment Charges on Loans) Directions, 2025 — the governing rule: The RBI (Pre-payment Charges on Loans) Directions, 2025 prohibit banks, co-operative banks, and all other RBI-regulated lenders from levying prepayment, foreclosure, or part-payment charges on floating-rate loans to individual borrowers for non-business purposes. The protection has no minimum lock-in period, no restriction on source of funds, and applies regardless of loan size. It covers:
- Home loans on floating rate
- Car loans on floating rate (note: many car loans from NBFCs are fixed-rate — verify)
- Personal loans on floating rate (note: most personal loans are fixed-rate — verify)
- Education loans on floating rate
- Any other individual retail loan at a floating rate for non-business purposes
Extension from 1 January 2026: For loans sanctioned or renewed on or after 1 January 2026, the Directions also extend this protection to floating-rate business loans taken by individuals and MSEs. If you have a business loan in your name at a floating rate, sanctioned or renewed on/after that date, prepayment charges are prohibited.
Fixed-rate loans are not covered: The 2025 Directions explicitly exclude fixed-rate loans. Lenders may still levy prepayment or foreclosure charges on fixed-rate loans, provided these are reasonable, board-approved, and disclosed upfront in the loan agreement. Typical fixed-rate charges: 2–4% for home loans, 3–6% for car loans, 2–5% for personal loans. These appear in your sanction letter's prepayment clause.
How to determine if your loan is floating or fixed: Check your sanction letter's Rate of Interest section. A floating-rate loan references a benchmark: EBLR (External Benchmark Lending Rate — linked to RBI repo rate), MCLR (Marginal Cost of Funds-based Lending Rate), or Base Rate. A fixed-rate loan states a fixed percentage with no benchmark link. Most home loans from scheduled commercial banks after 2019 are EBLR-linked (floating). Most personal loans and car loans from NBFCs are fixed-rate — for these, the Directions' ban does not apply.
Tax on home loan — what prepayment affects: For borrowers in the old tax regime: home loan interest is deductible under Section 24(b) up to ₹2L/year (self-occupied property). Principal repayment — including lump sum prepayments — qualifies as Section 80C deduction up to ₹1.5L/year across all 80C instruments. This means a ₹3L prepayment may qualify for ₹1.5L in 80C deduction in the year of prepayment (if 80C headroom exists). Net effect: prepayment is still beneficial even in the old regime. In the new tax regime, neither Section 24(b) nor 80C is available.
Prepayment vs investing — general heuristic: If your loan rate is higher than your post-tax investment return at equivalent risk, prepay. If your loan rate is lower than your post-tax investment return at equivalent risk, invest. At 8.5% floating home loan rate vs equity at approximately 10–12% CAGR (higher risk, not guaranteed), the decision depends on risk appetite. At 16% personal loan rate vs any investment class, prepayment wins unambiguously — no standard investment reliably earns 16% guaranteed.
What Loan Prepayers Get Wrong
Not knowing the RBI floating-rate rule — and paying a penalty that wasn't owed. Many borrowers with floating-rate home loans pay prepayment penalties because the bank's branch staff erroneously collect them, or because the borrower doesn't know the rule. Under the RBI (Pre-payment Charges on Loans) Directions, 2025, no regulated lender can charge this fee on a floating-rate individual loan for non-business purposes. If you've been charged a prepayment penalty on a floating-rate loan, you can file a complaint with the bank's Grievance Redressal team and, if unresolved, escalate to the RBI Ombudsman under the Integrated Ombudsman Scheme.
Prepaying a fixed-rate loan without checking if the penalty cancels the benefit. On a short-tenure fixed-rate loan (3–4 years remaining), the interest saving from prepayment may be modest. A 3% penalty on ₹5L is ₹15,000 upfront — if the remaining interest on that ₹5L over 3 years at 9% is approximately ₹75,000, the net benefit is ₹60,000. If the remaining tenure is 1 year, the interest on ₹5L over 1 year is ₹45,000 — penalty ₹15,000 eats 33% of the benefit. Always run this calculator before prepaying a fixed-rate loan to verify the penalty is worth paying.
Prepaying in late tenure instead of early. The interest saved from prepaying in Year 15 of a 20-year loan is far less than the same prepayment in Year 3 — because most of the interest is already paid in the first half of the loan (front-loaded in the amortisation schedule). If you have the option of prepaying today vs 5 years from now, early prepayment almost always wins by a substantial margin.
Choosing tenure reduction without considering EMI reduction for cash flow needs. Keeping EMI constant and reducing tenure saves more total interest — but if your cash flow tightens unexpectedly (job change, medical expenses), the higher EMI becomes a burden. If there's real uncertainty about monthly income over the next 2–3 years, choosing the lower EMI option gives flexibility. Neither is universally correct — match the choice to your financial stability.
Frequently Asked Questions
Can the bank charge a prepayment penalty on my floating-rate home loan?
No. Under the RBI (Pre-payment Charges on Loans) Directions, 2025, banks and all RBI-regulated lenders are prohibited from charging any prepayment, part-payment, or foreclosure fee on floating-rate loans to individual borrowers for non-business purposes. This applies to floating-rate home loans, car loans, personal loans, and education loans — with no minimum lock-in and no restriction on amount or source of funds. From 1 January 2026, the protection also extends to floating-rate business loans to individuals and MSEs (loans sanctioned/renewed on or after that date). Fixed-rate loans are not covered — lenders can charge disclosed, board-approved foreclosure fees on fixed-rate home loans. Check your sanction letter's Rate of Interest section: floating rate references EBLR or MCLR; fixed rate states a fixed percentage.
How much interest does a ₹3L prepayment save on a ₹30L home loan?
On a ₹30L home loan at 8.5% for 20 years (EMI ₹26,034), prepaying ₹3L in Year 3 saves approximately ₹7.93L in total interest and cuts 42 months off the tenure (keeping EMI constant). The earlier the prepayment, the more interest saved — the same ₹3L prepaid in Year 1 saves approximately ₹8.4L. Prepaid in Year 10, savings drop to approximately ₹4.6L. Use this calculator with your exact loan details for a precise figure.
Should I reduce EMI or reduce tenure after prepayment?
Reducing tenure (keeping EMI constant) saves significantly more total interest. The loan ends sooner, so the outstanding balance on which interest accrues is retired faster. Example: on ₹30L at 8.5%, a ₹3L prepayment at Year 3 with tenure reduction saves ₹7.93L. Taking the EMI reduction instead saves less because the loan runs for the original 20 years, just with a slightly smaller principal from month 37. Choose tenure reduction if your monthly cash flow is stable; choose EMI reduction if you need monthly relief.
Is a lump sum prepayment better than regular part-prepayments?
The timing of prepayment matters more than whether it's lump sum or spread out. Prepaying ₹3L in one shot in Year 3 saves more than spreading ₹25,000/month over the next 12 months — because the full ₹3L reduces the principal balance immediately, and interest savings begin from the next EMI. If you receive a windfall (bonus, maturity proceeds), deploy it as a single prepayment rather than holding it to spread over months.
Does prepaying a home loan affect my Section 80C tax benefit?
In the old tax regime: home loan principal repayment (including lump sum prepayments) qualifies as a Section 80C deduction up to ₹1.5L per year across all 80C instruments. A ₹3L lump sum prepayment may be claimable as 80C in the year of payment — if you have unused 80C headroom. This makes the prepayment tax-efficient in the old regime. In the new tax regime: no Section 80C deductions are available at all — neither for regular principal EMI nor for prepayments. Section 24(b) interest deduction is also unavailable in the new regime.
Should I prepay my home loan or invest the money?
The break-even rule: if your post-tax loan rate > post-tax investment return, prepay. If investment return > loan rate, invest. For a floating-rate home loan at 8.5%: prepaying saves a guaranteed 8.5% (post-tax if no Section 24(b) applicable, or slightly less in old regime with deduction). Equity mutual funds have historically delivered 10–12% CAGR (not guaranteed), post-tax approximately 9–10.5% after LTCG. For risk-tolerant investors with 10+ year horizon, equity investment is marginally better on expected value. For risk-averse investors or those in new regime (no interest deduction), the 8.5% guaranteed saving is highly competitive.
Can I make multiple partial prepayments or just one?
Most banks allow unlimited partial prepayments on floating-rate loans — no minimum amount required and no fee (per the RBI (Pre-payment Charges on Loans) Directions, 2025, which prohibit prepayment charges on floating-rate individual loans for non-business purposes). Some banks may require a minimum prepayment amount (e.g., 1 or 2 months' EMI as a minimum chunk) — check your loan agreement. Each partial prepayment reduces the outstanding principal, and the subsequent interest saving compounds from that reduction onward. Multiple small prepayments spread over years are less effective than single larger prepayments, but still beneficial.
What is the best time in the loan tenure to prepay?
Earlier is always better for maximum interest saving. In the first half of a home loan tenure, EMIs are heavily interest-weighted — a large fraction of each payment is interest, not principal. A prepayment in Year 3 of a 20-year loan saves more than twice the interest that the same prepayment saves in Year 15. The table on this page shows this clearly. If you receive a windfall early in your loan — inheritance, bonus, maturing investment — deploying it as a prepayment in the early years is almost always optimal.