How Much Should You Prepay on Your Home Loan? A Practical Framework

You got a bonus. Or sold some mutual funds. Or received a gift. Now the question is: how much of this windfall should go toward prepaying your home loan?

This is one of the most common — and most poorly answered — questions in Indian personal finance. Here is a framework that actually works.

Step 1: Protect your emergency fund first

Before any prepayment, make sure you have 6 months of expenses in a liquid fund or savings account. A home loan is a long-term commitment. Losing your job or facing a medical emergency while you have no liquidity is far more damaging than carrying extra loan interest for a few months.

Rule: Never prepay if it drops your liquid savings below 6 months of expenses.

Step 2: Compare your effective loan rate vs your investment rate

Your home loan has an interest rate — say 8.5%. But your effective rate is lower after tax benefits.

Under Section 24(b), you can deduct up to ₹2 lakh of home loan interest annually. If you're in the 30% bracket, that's ₹60,000 in tax saved — effectively subsidising your loan.

Formula:

Effective loan cost = Interest rate × (1 − your tax rate)

For 8.5% at 30% bracket:

8.5% × (1 − 0.30) = 5.95% effective cost

Now compare this to what your money earns:

• Savings account: ~3.5% — prepay
• Debt mutual fund: ~6.5% — borderline, consider risk
• Equity SIP (long-term average): ~12% — invest, don't prepay
• PPF: 7.1% (tax-free) — PPF wins over a 5.95% effective rate

Rule: If your post-tax investment return exceeds your effective loan cost, invest the surplus. If not, prepay.

Step 3: Factor in where you are in the loan

Interest is front-loaded in EMI loans. In the first 5 years of a 20-year loan at 8.5%, roughly 75–80% of each EMI goes toward interest. A prepayment in year 2 saves dramatically more than the same amount in year 15.

Prepayment impact by year (₹1 crore loan, 8.5%, 20 years):

Prepayment of ₹5 lakh in...	Interest saved	Tenure cut
Year 1	~₹8.2 lakh	~2 years 1 month
Year 5	~₹5.8 lakh	~1 year 5 months
Year 10	~₹3.1 lakh	~9 months
Year 15	~₹1.1 lakh	~3 months

The earlier the prepayment, the more it multiplies. Use the prepayment calculator to see the exact numbers for your loan.

Step 4: Check for prepayment charges

RBI mandates that banks cannot charge prepayment penalties on floating rate home loans. If your loan is floating rate (MCLR or repo-linked), prepayment is always free.

Fixed rate loans may have a penalty of 2–3% of the prepaid amount. Factor this in before deciding.

Rule: If there's a 2% penalty on ₹5 lakh, that's ₹10,000 gone immediately. Your prepayment needs to save more than that in interest to be worthwhile — it almost always does if you're in the first half of your tenure.

Step 5: Choose the right frequency

One-time large prepayments vs. small monthly extra EMIs — which is better?

Both reduce interest, but for most people annual lump sums (bonus season, tax refund) are more practical. Monthly extra EMIs require consistent discipline and may strain cash flow.

A useful rule of thumb: one extra EMI per year can cut 2–3 years off a 20-year loan. Model it at LoanClarity to see your exact figure.

The Decision Tree

Do you have 6 months emergency fund?
  No → Build it first. Then revisit.
  Yes ↓

Is your effective loan cost < post-tax investment return?
  Yes → Invest the surplus (equity SIP, PPF)
  No ↓

Are you in the first half of your loan tenure?
  Yes → Prepay aggressively (high impact)
  No → Prepay moderately (lower impact, consider investing)

Is the prepayment amount > 5% of outstanding principal?
  Yes → Choose reduce tenure (maximum interest saving)
  No → Either option works, reduce tenure still preferred

Bottom line

For most Indian home loan borrowers on floating rates with standard tax deductions, the breakeven is around 7.5–8% — if your loan rate is above this and your investment returns are below this, prepay. If your loan rate is below 7.5% (after Section 24 benefit), a well-run equity portfolio should outperform it over the long run.

Model your exact scenario — with your actual rate, outstanding principal, and tenure — using the Home Loan Prepayment Calculator.