Mortgage vs Stock Market

Analyze the opportunity cost of debt repayment versus wealth building.

Decision Factors

Extra Monthly Payment ($)

Mortgage Rate (%)

Invest Return (%)

Timeframe (Years)

Tax Deductible?

Mortgage Interest deduction

Psychologically, being debt-free is great. Mathematically, investing is better if the market return exceeds your effective mortgage rate.

Optimization Result

Investing Wins

By $112,452 after 15 years

Investment Path

$378,406

Growth at 9%

Mortgage Path

$265,954

Savings at 6.5%

Effective Mortgage Rate4.94%

Total Capital Deployed$180,000

Opportunity Cost

The "Spread" Strategy

Risk Profile

Guaranteed vs. Variable

The Mathematical Choice

When you have extra cash, you face a common dilemma: reduce your liabilities (mortgage) or increase your assets (stocks/bonds). The right answer depends on the "Spread"—the difference between your mortgage interest rate and your expected investment return.

Paying Down Mortgage

Paying down a mortgage at 6.5% interest is mathematically equivalent to a **guaranteed 6.5% return** on your money. It's a risk-free investment in your own equity.

Investing in Stocks

The S&P 500 has historically returned ~10% annually. If your investment return is higher than your mortgage rate, you build more wealth over time by investing. However, this return is **not guaranteed**.

Tax Implications in the USA

The US tax code often favors debt in two ways:

Mortgage Interest Deduction: If you itemize, you can deduct mortgage interest, which lowers your "Effective Interest Rate."
Capital Gains Tax: Investing in a taxable account incurs taxes on profits, which reduces your "Effective Investment Return."

Note: This tool uses simplified logic. Consult a financial advisor for specific tax and investment advice tailored to your 2024 tax bracket.

This calculator is part of our premier suite of Wall Street investment calculators. Explore the fullUS Stock Market Toolkitto optimize your strategy and manage risk like a professional.