"Should I aggressively pay off my loans early, or should I take that extra cash and invest it in the market?"
It is perhaps the most heavily debated topic in personal finance. Depending on who you ask, you'll get fiercely different answers. Dave Ramsey will tell you to pay off every single penny of debt before investing a dime. Other financial advisors will tell you that paying off a 3% mortgage early is financially irrational when the stock market historically returns 8-10%.
So, who is right? The answer lies in the math. It ultimately boils down to a single comparison: the interest rate of your debt versus the expected return rate of your investment.
The Mathematical Showdown Calculator
Let's take the emotion out of it. Enter your current debt amount, its interest rate, and what you realistically believe you could earn if you invested that money instead. We will show you which scenario leaves you mathematically wealthier.
When to Ignore the Math
Calculators are logical, but humans are emotional. While the math above is correct, it assumes two things: you will actually invest the money (and not spend it), and you can sleep soundly at night while holding debt.
High-Interest Debt (> 8%)
Credit cards, personal loans, and some auto loans. Always pay this off first. It is nearly impossible to safely out-invest an 18% credit card interest rate. Paying this off is a guaranteed 18% return on your money.
Moderate-Interest Debt (5% - 8%)
Student loans and some car loans. This is the gray area. It depends on your risk tolerance. A balanced approach—splitting your extra cash 50/50 between debt payoff and investing—is often a great psychological compromise.
Low-Interest Debt (< 5%)
Mortgages and subsidized loans. Mathematically, you should almost always drag this debt out for as long as possible and invest the difference in broad-market index funds.