Prepay vs Invest Calculator

Prepay your home loan or invest the surplus? See which wins

Reviewed by the PaisaTools Editorial Team · Last reviewed September 2026

How to use: Enter your outstanding loan, rate, tenure and the spare cash you have each month — we compare prepaying vs investing it and tell you which leaves you richer.

Example₹40L loan @ 8.5% over 15y, ₹20,000/month spare, 11% returns → see whether prepaying or investing wins

How much loan is left?

₹

How much principal is still left on the loan

At what loan rate?

Your current home-loan rate

How many years are left?

yrs

How much spare each month?

₹

The surplus you'd either prepay with OR invest

What return if you invest?

%/yr

What you'd earn investing instead (e.g. index funds ~11–12%)

Verdict by end of tenure

Investing wins by ₹11,10,475

With a 8.5% loan and 11% returns, investing the surplus leaves you about ₹11,10,475 better off by the end of your tenure.

If you PREPAY

₹79,83,317

If you INVEST

₹90,93,791

✓ Better outcome

Investment pot each path builds by the end of your original tenure (the loan is fully paid in both cases).

The numbers behind it

Current EMI₹39,390/mo

Prepaying clears the loan7.3 yrs early

Interest saved by prepaying₹16,35,098

The deciding ruleReturn > loan rate → invest

Rule of thumb: if your return beats your loan rate, invest; if your loan rate is higher, prepay. Prepaying is a guaranteed, risk-free saving; investing carries market risk for a (usually higher) expected return.

See your full EMI & amortization schedule

How it works

Prepay the home loan or invest the spare cash? It feels like a gut call, but it's really one number against another — your loan interest rate versus the return you'd earn investing. This calculator settles it with a year-by-year race over your remaining tenure.

It deploys the same monthly surplus two ways. Prepay: add it to your EMI so the loan clears years early, then invest the freed-up cash for the rest of the term. Invest: keep paying the normal EMI and invest the surplus the whole time. At the end both have the loan fully paid — so it compares the investment pot each path built, and declares the winner plus the interest you'd save by prepaying.

The honest rule it surfaces: if your return beats your loan rate, invest; if your loan rate is higher, prepay. Prepaying is a guaranteed, risk-free return; investing carries market risk for a usually-higher expected one. Once you decide, model the exact payoff with our EMI calculator.

Method & sources

The comparison runs a monthly amortisation of your loan with and without the extra payment (standard EMI formula), then compounds the relevant monthly surplus at your expected return (future value of an annuity) to the end of the original tenure. It is pre-tax on both sides and excludes the Section 24(b) interest deduction and LTCG on investments — both noted above — so the result is conservative and educational, not financial advice. Investment returns are not guaranteed; past performance doesn't predict the future.

What this doesn't cover

The verdict hinges entirely on the loan rate vs the return you assume.
Ignores tax on investment gains and any loan-interest deduction.

Frequently asked

Should I prepay my home loan or invest the money?: It comes down to one comparison: your loan's interest rate vs the return you can earn by investing. If your expected return is higher than your loan rate, investing the surplus usually builds more wealth by the end of your tenure. If your loan rate is higher, prepaying wins. This calculator runs both paths on your exact numbers and shows the gap.
Why isn't prepaying always the right move?: Because money invested can grow faster than the interest you'd save. On an 8.5% loan, prepaying 'earns' you a guaranteed 8.5%. But if you can reasonably expect ~11–12% from diversified equity over the long run, investing the same surplus leaves you with more — even after the loan is cleared on schedule. The trade-off is risk: prepaying is certain, investing is not.
What's the simple rule of thumb?: Return beats loan rate → invest. Loan rate beats return → prepay. Near equal → it's a wash, so let other factors decide (peace of mind from being debt-free, your risk appetite, job stability).
Does the home-loan tax benefit change the answer?: Yes, in favour of NOT prepaying. The Section 24(b) (section 22 of the new Income-tax Act, 2025) deduction (up to ₹2 lakh of interest) lowers your effective loan rate, which makes investing relatively more attractive. This calculator is deliberately pre-tax and conservative; if you claim the deduction, the case for investing is a bit stronger than shown.
Are investment returns taxed in this comparison?: The model is pre-tax on both sides for simplicity. In reality long-term equity gains attract 12.5% LTCG above ₹1.25 lakh/year, which slightly trims the investing side. The interest saved by prepaying is effectively tax-free. For most realistic rate gaps the verdict doesn't flip, but treat a close result as 'roughly even'.
Should I prepay in part or invest a lump sum instead?: The same rule applies to a one-time amount: compare your loan rate to your expected return. A useful middle path many people choose is to split the surplus — prepay enough to stay comfortable about the debt, and invest the rest for growth. Run both extremes here to see the size of the gap first.

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