APR vs effective rate, types of debt, and why understanding the difference saves you thousands.
Debt is borrowed money you promise to repay with interest. It's not inherently bad—it's a tool. A mortgage at 5% on an appreciating home builds wealth. A payday loan at 400% destroys it. The difference isn't the debt itself; it's the cost and what the money finances.
This guide shows you how debt actually works, what you'll really pay, and how to use it wisely.
APR (Annual Percentage Rate) is what lenders advertise. Effective Rate is what you actually pay when interest compounds. The difference is why payday loans are predatory.
Lenders advertise APR because it looks better than effective rate. A payday lender says "400% APR" knowing most people won't calculate what that actually means over 2 weeks. In reality, borrowing $300 for 2 weeks at 400% APR costs you $46 in fees — a 15% cost for 2 weeks, or 400% annualized. That's predatory.
Credit cards compound interest monthly, so the effective rate is only slightly higher than APR. But payday loans and other short-term debt compound so frequently that the effective rate becomes shocking. When comparing loans, always ask for the effective annual rate or calculate total cost yourself.
Highest interest rate of any common consumer debt. Carrying a balance is one of the fastest ways to destroy wealth.
Not all debt is the enemy. Understanding the difference between debt that builds wealth and debt that destroys it is one of the most important financial literacy concepts.
Good debt has a low interest rate, finances an asset that appreciates or generates income, and has a clear repayment timeline. A mortgage at 5% on a home that appreciates at 4-6%/year can build wealth over time. A student loan for a nursing or engineering degree with strong employment outcomes is an investment in future earnings. The test: will this debt make me richer or poorer in 10 years?
Bad debt finances things that lose value immediately or carries interest rates so high that the cost destroys wealth faster than any investment can build it. A $5,000 credit card balance at 20% costs $1,000/year just to stand still. A payday loan of $300 can cost $60-$90 in fees for 2 weeks — over 400% annualized.
Some debt is neither clearly good nor bad — it depends on the rate, your alternatives, and your discipline. A car loan at 4.9% for a reliable vehicle you need for work is reasonable. A HELOC at prime + 0.5% used to renovate a kitchen is arguably wealth-building. The same HELOC used for a vacation is bad debt with a low rate.