Loan vs Investment Calculator – Prepay or Invest?

Compare whether you should use your extra funds to prepay an existing loan or invest them in the market. Find out which path generates more net wealth for you over the long term.

Loan Profile

The Choice

Mathematical Advantage

Calculating...

Interest Avoided (Prepay)

₹0

Interest expense prevented by paying off principal early.

Wealth Gained (Invest)

₹0

Total profit earned by investing the extra funds.

Outcome Comparison

Loan Interest Savings ₹0
Investment Final Value ₹0
Net Wealth Difference ₹0

Should I Prepay My Loan or Invest?

One of the most debated topics in personal finance is whether to prioritize debt repayment or market investment when you have extra cash. The answer lies in a concept called Spread Analysis—the difference between your loan interest rate and your expected investment return rate.

While prepaying a Home Loan provides a guaranteed "return" (by avoiding interest cost), investing in SIPs offers potentially higher, albeit market-linked, returns. This calculator compares the two paths over your remaining loan tenure to help you maximize your net worth.

Understanding Opportunity Cost

Every rupee you use to prepay a loan has an Opportunity Cost—the potential profit that money could have earned if it were invested elsewhere. Conversely, every rupee you invest instead of prepaying a loan has a Debt Cost—the interest that the bank continues to charge on that portion of the principal.

In high-inflation environments, debt becomes cheaper to carry over time, making investing more attractive. However, for high-interest liabilities like credit cards or personal loans, prepayment is almost always the mathematically superior choice.

Financial Strategy: Debt vs Equity

When Prepayment Wins

If your loan rate is above 12% (e.g., Personal Loans) or if you are in the first 5 years of a Home Loan where interest components are highest. Prepayment also reduces psychological stress.

When Investing Wins

If your loan rate is low (e.g., subsidized Home Loans at 8%) and you are investing in growth assets like Equity MFs targeting 12-15% returns over 10+ years.

Frequently Asked Questions

Should I prepay loan or invest?
Mathematically, you should choose the option with the higher percentage. If investment return > loan interest, invest. Otherwise, prepay.
Is loan prepayment better than SIP?
Prepayment gives a 100% guaranteed 'return' of the interest saved. SIP returns are subject to market volatility but historically provide higher long-term growth in India.
What interest rate makes prepayment better?
Generally, if your loan rate is above 10-12%, prepaying is safer and smarter. If it's below 9% (like Home Loans), investing in diversified equity funds is often better.
Does the home loan tax benefit change the decision?
Yes. If you are in the Old Tax Regime, the effective interest rate of your home loan is lower because of tax deductions. This makes carrying the loan and investing elsewhere even more attractive.

Related Financial Tools

EMI Calculator

Prepayment

SIP Calculator

CAGR Tool

Net Worth

Disclaimer

Investment returns are market-linked and not guaranteed. Interest savings are based on standard reducing balance math. This tool provides mathematical estimations and does not constitute financial advice. Always consult a certified financial planner.

Last Updated: March 2026