6 free calculators that show the real cost of your debt — and the fastest, cheapest way out of it.
Every other hub on this site is about opportunity cost — what you could earn if you invested instead of spent. Debt flips that math: instead of a maybe-future gain, you have a guaranteed, contractual cost in the form of interest. The Federal Reserve's G.19 Consumer Credit report shows average credit card APRs sitting well above 20% — a rate that, mathematically, almost no diversified investment beats consistently.
That means paying down high-interest debt isn't just "responsible" — it's often the single highest guaranteed return available to you. The calculators below quantify exactly how much that debt is costing you, and how different payoff strategies compare.
Two ideas run through every tool here: the order in which you pay off multiple debts changes the total interest paid (see Avalanche vs Snowball), and extra payments early in a loan's life compound their savings over the full remaining term (see Mortgage Overpayment).
| Calculator | What it answers | Best for |
|---|---|---|
| Credit Card True Cost | Total interest paid on a balance at a given APR and payment | Anyone carrying a credit card balance |
| Car Loan True Cost | Total interest + depreciation impact of a car loan | Buying or refinancing a car |
| Student Loan Payoff | Time and interest to pay off student loans at various payments | Anyone with student loan debt |
| Mortgage Overpayment | Interest saved and years shaved off by paying extra principal | Homeowners with a mortgage |
| Buy Now, Pay Later | Real cost of BNPL plans including late fees | Frequent BNPL users (Klarna, Affirm, etc.) |
| Avalanche vs Snowball | Which payoff order saves more on multiple debts | Anyone with 2+ debts to pay off |