Credit Card Debt
On a $5,000 balance, minimum-only payments stretch to 234 months. See how minimum payments and daily interest keep a balance alive — and the math that kills it.
Explore credit card debt →
Personal finance, with the math shown
Your money questions, answered with the actual math.
Dollar Doctrine explains how credit card interest, car loans, mortgages, Fed decisions and paychecks really work — every number calculated step by step, sources cited.
Start with credit card debt Watch on YouTubeSix topics, one rule: show the numbers
Every topic on this site follows the same rule: no claim without the calculation behind it. Pick the question that is costing you money right now.
Auto Loans
On a $40,000 loan, the term you pick changes the interest you pay by thousands. Compare the real cost of each term length, side by side.
Explore auto loans →Mortgages & Housing
What an $80,000 salary can actually carry — how lenders turn income and a mortgage rate into the house price and monthly payment you can support.
Explore mortgages & housing →The Fed & Your Wallet
Why a Fed cut doesn't always lower your rates. How Federal Reserve decisions reach — and sometimes never reach — your card APR, savings yield, and mortgage rate.
Explore the Fed & your wallet →Paychecks & Taxes
Where the missing chunk of your salary goes. Your paycheck, line by line: FICA, federal withholding, and state withholding.
Explore paychecks & taxes →Debt Payoff Strategies
Avalanche vs snowball, run on the same debts. Two payoff orders, one set of balances — see which one costs less and why.
Explore debt payoff strategies →Start with these guides
What Is a Good APR for a Credit Card?
The average card APR is 22.36% — is yours good? Benchmark your card against the average and see what each APR tier really costs.
Read the guide →How Is Credit Card Interest Calculated?
The average daily balance method, worked out day by day — so you can check any statement against the math yourself.
Read the guide →Debt Avalanche vs Debt Snowball
Same $7,000 of debt, two payoff orders — one costs $34.38 less. Both methods, run in full, with the winner shown in the numbers.
Read the guide →Why trust these numbers?
- Every figure is calculated on the page or cited. Benchmarks and rates come from public sources such as the Federal Reserve, Freddie Mac, and the IRS — named where the number appears.
- Worked examples state their assumptions. Each example shows the balance, rate, and payment it starts from, so you can re-run the math with your own numbers.
- Educational only, never personalized advice. These guides explain how the math works in general; they are not a recommendation for your situation. See how we calculate for the formulas and sources behind every page.
Prefer to watch?
The Dollar Doctrine YouTube channel covers the same topics on video — credit cards, car loans, mortgages, the Fed, and paychecks, with the numbers worked out on screen.
Watch on YouTube