Your credit score is a three-digit number that lenders use to predict how likely you are to repay debt. It affects the interest rate on your mortgage (potentially tens of thousands of dollars), whether you qualify for an apartment, what you pay for car insurance in many states, and occasionally whether you get a job offer.
Understanding how it's actually calculated — and what's a myth — is more valuable than most financial advice.
Disclaimer: This article is for educational purposes only and does not constitute financial advice. Consult a licensed financial advisor before making financial decisions.
The Score Range and What It Means
The most widely used scoring model is FICO, ranging from 300 to 850.
| Score Range | Category | What It Means | |---|---|---| | 800–850 | Exceptional | Best rates on everything | | 740–799 | Very Good | Near-best rates | | 670–739 | Good | Qualify for most loans at reasonable rates | | 580–669 | Fair | Higher rates, may require co-signer | | Below 580 | Poor | Difficulty qualifying; secured cards only |
The difference between a 620 and a 760 score on a $300,000 30-year mortgage is approximately $80,000–$120,000 in total interest paid, depending on the rate environment. Your credit score is worth actively managing.
The Five FICO Factors
1. Payment History — 35% The single most important factor. Every on-time payment strengthens it; every missed payment damages it. A 30-day late payment can drop a good score by 80–100 points. A 90-day late drops it further and stays on your report for 7 years. Set up autopay for at least the minimum payment on every account to prevent accidental misses.
2. Amounts Owed (Credit Utilization) — 30% The percentage of your available revolving credit you're currently using. $2,000 balance on a $10,000 limit = 20% utilization. Lower is better. Above 30% starts to hurt. Above 50% hurts significantly. The ideal for maximum score: under 10%.
This is calculated per card AND across all cards. Having one card maxed out hurts even if your total utilization is low.
3. Length of Credit History — 15% Average age of all accounts plus age of your oldest account. This rewards patience. Opening many new accounts at once tanks this metric. Closing old accounts shortens your average history — generally don't close old cards, even if you don't use them.
4. Credit Mix — 10% Having both revolving credit (credit cards) and installment loans (mortgage, auto, student loans) is slightly better than one type alone. This factor matters least and isn't worth taking on debt to improve.
5. New Credit (Hard Inquiries) — 10% Every time you apply for new credit, the lender does a "hard pull" which temporarily reduces your score by 5–10 points. Multiple mortgage or auto loan inquiries within a 14–45 day window are treated as a single inquiry (rate shopping). Credit card applications are each counted separately.
Common Myths
Myth: Checking your own credit hurts your score. False. Checking your own credit is a "soft pull" and has zero impact on your score. Check it as often as you like.
Myth: Carrying a small balance builds credit. False. Carrying a balance just costs you interest. Paying in full builds credit identically to carrying a balance — payment history is what matters, not whether you pay interest.
Myth: Income affects your credit score. False. FICO scores don't include income, employment status, or net worth. High earners can have terrible scores; low earners can have excellent scores.
Myth: Closing old credit cards improves your score. Usually false. Closing a card reduces your available credit (increases utilization) and may shorten your average account age. Both hurt your score.
Myth: You need to pay a credit repair company. Almost always unnecessary. Legitimate negative items cannot be removed before their time. What credit repair companies do, you can do yourself for free: dispute errors with the credit bureaus.
How to Actually Improve Your Score
The fast levers (results in 1–3 months):
- Pay down credit card balances to under 10% utilization — this is the fastest score boost available
- Pay off any collection accounts (with a "pay for delete" letter if possible)
- Dispute errors on your credit report (get your free reports at annualcreditreport.com)
The slow levers (results in 6–24 months):
- Establish 12+ months of on-time payment history
- Keep old accounts open
- Add yourself as an authorized user on a family member's old, well-maintained card (adds their history to yours)
What does NOT help:
- Paying a credit repair company
- Disputing accurate negative information
- "Rapid rescoring" services marketed to consumers
Monitoring Your Score
You're entitled to one free credit report per year from each of the three bureaus (Equifax, Experian, TransUnion) at annualcreditreport.com. Many credit card issuers also provide free monthly FICO score updates.
Check for errors — roughly 1 in 4 credit reports contains errors significant enough to affect a lending decision. Disputing errors is free and the bureau must investigate within 30 days.
Your credit score is one of the few financial metrics where understanding the scoring formula almost entirely tells you how to optimize it. There's no mystery, no inside trick. Pay on time, keep balances low, don't open a lot of new accounts, and let time do the rest.