Loan Prepayment vs. Investing: A Side-by-Side Comparison
Loan Prepayment vs. Investing: The Short Answer
Verdict: prepay when your expected post-tax return is below your loan rate; invest the difference when you expect to beat it. Prepayment is a guaranteed investment that pays exactly your loan rate, tax-free: money sent against an 8.5% home loan earns 8.5% the moment it clears. Investing can pay more over long horizons, but only as an expectation, carried through market risk.
| Prepay the loan | Invest the difference |
|---|---|
| You earn: your loan rate, certain (8.5%) | You earn: market return minus tax, uncertain |
| Risk: none; the saving locks in | Risk: drawdowns; returns can lag for years |
| Liquidity: falls, since the money sits inside the loan | Liquidity: stays available |
The one-line rule
Your loan rate is the break-even: below it, prepaying wins; above it, investing wins.
Loan Prepayment vs. Investing: The Numbers, Matched Rupee for Rupee
Give both paths the same money. On a ₹50 Lakh home loan at 8.5% for 20 years, the EMI is ₹43,391 and total interest is ₹54.14 Lakh. Commit the same ₹53,391 a month (the EMI plus ₹10,000 extra) on both paths for all 20 years:
| At month 240 | Prepay path | Invest path |
|---|---|---|
| How it runs | Loan closes at month 155 (about 12.9 years); the freed ₹53,391 is invested from month 156 | The EMI runs all 240 months while ₹10,000/month goes into equity at 12% |
| Total interest paid | ₹32.35 Lakh | ₹54.14 Lakh |
| Corpus at 12% | ≈ ₹70.0 Lakh | ≈ ₹92.0 Lakh |
| After 12.5% LTCG on gains | ≈ ₹67.0 Lakh | ≈ ₹83.6 Lakh |
The roughly ₹22 Lakh pre-tax gap is the opportunity cost of certainty, and it materializes only if the ₹10,000 is genuinely invested every month. A smaller prepayment locks in the same 8.5%: an extra ₹5,000/month closes the loan in 187 months and saves ₹13.9 Lakh in interest.
The loan type sets the default
| Loan type | Typical rate | Horizon | Default call |
|---|---|---|---|
| Home loan | 8.5% | 15–20 years | Investing usually ahead, if the difference is actually invested; Section 24(b) deductions shift the math further that way |
| Car loan | 9.5% | 5 years | Close call. The short horizon favors prepayment’s certainty |
| Personal loan | 12–14% | Short | Prepay first. It beats realistic equity returns after tax |
For the full walkthrough and the behavior traps, read Loan Prepayment vs Investing: Which Builds More Wealth?.
Loan Prepayment vs. Investing: Break-Even, Tax Drag and Edge Cases
Prepayment behaves like a bond that pays your loan rate, with no taxable event:
The investing side must clear the same bar after tax, where is the tax applied to gains:
Equity LTCG applies at 12.5% above the ₹1.25 Lakh annual exemption, which is why the matched cash flows finish near ₹67.0 Lakh versus ₹83.6 Lakh after tax: still ahead, but narrower than the pre-tax gap. Run the same cash flows at an 8.5% investment return and the paths land level. That is why the break-even is your loan rate, not a market forecast.
Two regulatory details sharpen the call. RBI’s fair-practices code bars prepayment penalties on floating-rate home loans, so extra payments cost nothing. Section 24(b) allows interest deduction up to ₹2 Lakh a year on a home loan, old regime only, and if you claim it, your effective loan rate falls, pushing the break-even further toward investing.
Edge cases: a pre-tax 12% equity figure is a CAGR-style expectation (smooth in a model, lumpy in reality) while a 12–14% personal loan pays that rate with certainty. Prepay it first. Model both sides with the Loan Prepayment Calculator and the SIP Calculator.