How Credit Scores Actually Work (and What Moves Them)

Your credit score is not a mystery, and it's not a grade of how responsible you are. It's a prediction: how likely are you to pay a lender back on time? Five factors build that prediction, and their weights are public.

1. Payment history — 35%. The single biggest factor. One missed payment can drop a good score by 80-120 points, and it stays on your report for seven years. The good news: lenders generally report monthly, so a single late payment fades in importance as clean months pile up behind it.

2. Amounts owed — 30%. Mostly this means utilization: how much of your available credit you're using. The practical rule is to keep each card under 30% of its limit, and under 10% is better still. Crucially, utilization has no memory — pay the balance down and the score recovers within a billing cycle or two. This is why someone can raise a score fast before a mortgage application by paying cards down before the statement closes.

3. Length of credit history — 15%. Older average age is better. This is why you shouldn't close your oldest card: the account keeps aging and keeps its limit in your utilization math. Close it and both benefits vanish.

4. New credit — 10%. Each hard inquiry can shave a few points for about a year. Rate-shopping is handled gracefully — multiple mortgage or auto loan inquiries within a 14-45 day window count as one.

5. Credit mix — 10%. A mix of revolving (cards) and installment (loans) helps slightly. Never take out a loan to game this factor.

Two habits outrank every optimization. First, never miss a payment — autopay the minimum on every card as insurance, even if you pay in full manually. Second, pay your balance before the statement closes, because that's the number most issuers report to the bureaus. A card you pay in full every month can still show high utilization if the statement snapshot catches the balance mid-spend.

What doesn't affect your score, despite the myths: your income, your debit card activity, checking your own credit (soft pulls are invisible), and carrying a balance — paying interest builds nothing. Paying in full builds the same score.

Checking your credit reports is free and safe. The three bureaus let you pull reports weekly at annualcreditreport.com — the official, genuinely free site. Errors are common enough that a once-a-year review is worth the ten minutes, especially before a big loan.

The score's real job. A 760+ score versus a 620 score on a $350,000 mortgage is roughly a 1.5% rate difference — around $100,000 over a 30-year loan. That's what those five factors are actually protecting.