Credit, cars, phones and housing
You just got your first credit card
A credit card lets you borrow money for purchases and pay it back later. Used one way it builds a credit history that saves you thousands; used another way it costs you thousands.
The difference comes down to a handful of terms — what the interest rate means, what the grace period is, what happens if you carry a balance. This section explains each of them and the habits that keep a card on your side.
Americans were charged $160 billion in credit card interest in a single year, up from $105 billion two years earlier, with average rates reaching 25.2%. Your statement is legally required to show what minimum payments will cost you — and almost nobody reads that box.
Source: Consumer Financial Protection Bureau, Consumer Credit Card Market Report, published in the Federal Register, January 2026; Credit CARD Act of 2009 disclosure requirement.
How the grace period works
If you pay your full statement balance by the due date, you pay zero interest on purchases. That's the grace period, and it's the whole game.
Carry a balance even once and you can lose that grace period until you're paid off in full again. Interest starts accruing on new purchases immediately.
What the minimum payment really is
The minimum payment is designed to keep you paying, not to get you out of debt.
APR stands for Annual Percentage Rate. It is the yearly cost of borrowing money, expressed as a percentage of what you owe — so a 24% APR means that carrying a $1,000 balance for a year costs you roughly $240 in interest. The higher the APR, the more expensive the debt.
This is compounding running against you. Apply the Rule of 72 from Section 8: 72 divided by 24 gives three, so a balance you never pay doubles in roughly three years.
Put $1,000 on a card at 24% APR and pay only the minimum, and you'll be paying for years and hand over hundreds in interest on top of the original thousand. Your statement is required to show you this — there's a box that tells you how long minimum payments will take and what it'll cost. Look at it. It's sobering and it's accurate.
Utilization, and why 30% is the number people repeat
Credit utilization is how much of your limit you're using. On a $500 limit, a $400 balance is 80% utilization, and that hurts your score even if you pay it off in full.
You have probably heard you should keep it under 30%. FICO says that is not quite right. On its own myFICO site, FICO states that the data does not support the idea that your score dips once you cross 30% — there is no cliff at that number. What is true is that lower is better: FICO says keeping it below 10% helps build and maintain a good score, and people with 850 scores average around 4.1%.
Two details most people miss, both from FICO. Your score looks at the highest utilization on any single card, not just your total across all of them — so one maxed card hurts even if everything else is empty. And 0% is not the target either: using a card lightly and paying it off tells the scoring model more than never using it at all.
The practical move: pay the card down before the statement closes, not just before the due date. Issuers usually report your balance on the statement date, so that is the number your score sees.
The expensive corners
Cash advances have no grace period. Interest starts the moment you take the money, usually at a higher rate, plus a fee.
Late payments can trigger a fee and, once you're 30 days late, a mark on your credit report that stays for years.
Annual fees are worth it on some cards and pointless on a first card. For your first card, look for no annual fee.
If you can't get approved
Look at a secured card. You put down a deposit — often a few hundred dollars — and that becomes your limit. Used well for six to twelve months, it builds real history and many issuers will graduate you to a regular card and return the deposit. Credit unions are often the friendliest place to start.
What you can do
- Set up autopay for the full statement balance, not the minimum.
- Put one small recurring charge on the card and nothing else for the first few months.
- Find the minimum payment warning box on your statement and read it.
- Keep the balance under 30% of your limit — under 10% if you can.
- Pull your free credit reports at annualcreditreport.com and check them.
Where to check this yourself
Credit card and credit score basics at consumerfinance.gov. Free reports at annualcreditreport.com.