How Credit Scores Work: The Complete Guide

What Is a Credit Score?

A credit score is a three-digit number, typically between 300 and 850, that represents how likely you are to repay borrowed money. Lenders use it to decide whether to approve your application and what interest rate to charge. A higher score means lower risk in their eyes, which translates to better terms for you.

Two companies dominate credit scoring in the United States: FICO and VantageScore. While both use data from your credit reports at Equifax, Experian, and TransUnion, they weigh that data slightly differently.

FICO vs. VantageScore

FICO scores are used in roughly 90% of lending decisions. Your FICO score requires at least one account that has been open for six months and at least one account reported to the bureaus within the last six months.

VantageScore is more lenient. It can generate a score with just one month of credit history and one account reported within the past 24 months. This makes it more accessible for people who are new to credit.

Both models use a 300-850 range and agree on the general tiers:

| Range | FICO Rating | VantageScore Rating | |-----------|---------------|---------------------| | 800-850 | Exceptional | Excellent | | 740-799 | Very Good | Good | | 670-739 | Good | Good / Fair | | 580-669 | Fair | Fair / Poor | | 300-579 | Poor | Very Poor |

In practice, a 750 FICO and a 750 VantageScore signal roughly the same thing: you are a reliable borrower.

The Five Factors That Determine Your Score

FICO publishes the approximate weight of each factor. Understanding these gives you a roadmap for improvement.

1. Payment History (35%)

This is the single biggest factor. It answers one question: do you pay your bills on time? Even one payment that is 30 days late can drop a good score by 60 to 100 points. The damage increases with the severity -- 60-day and 90-day late payments hurt more, and collections or charge-offs are the worst.

What to do: Set up autopay for at least the minimum payment on every account. If you miss a payment by a few days, call the issuer immediately. Many will not report it to the bureaus if you pay within 30 days and have a clean history.

2. Credit Utilization (30%)

Utilization measures how much of your available revolving credit you are using. If you have a $10,000 total credit limit across all cards and carry a $3,000 balance, your utilization is 30%.

Scores respond best when utilization stays below 30%, and people with the highest scores typically keep it under 10%. The calculation looks at both your overall utilization and the utilization on each individual card.

What to do: Pay your balance before the statement closing date, not just the due date. The statement balance is what gets reported to the bureaus. If you can, make multiple payments per month to keep reported balances low.

3. Length of Credit History (15%)

This factor considers the age of your oldest account, the age of your newest account, and the average age across all accounts. A longer track record gives scoring models more data points and generally improves your score.

What to do: Keep old accounts open even if you do not use them regularly. Closing your oldest card shortens your history and can also increase utilization by reducing your total available credit. Put a small recurring charge on old cards so the issuer does not close them for inactivity.

4. Credit Mix (10%)

Scoring models like to see that you can manage different types of credit -- revolving accounts like credit cards alongside installment accounts like auto loans, student loans, or a mortgage. You do not need one of every type, but having only credit cards is slightly less favorable than a mix.

What to do: Do not open a loan just to diversify your credit mix. This factor carries the least weight and the benefit rarely outweighs the cost of unnecessary debt. Let this improve naturally over time.

5. New Credit Inquiries (10%)

Each time you apply for credit and the lender pulls your report, it creates a hard inquiry. One or two inquiries have minimal impact, but several in a short period can signal financial stress. Hard inquiries stay on your report for two years but only affect your score for about 12 months.

What to do: Space out credit applications. When shopping for a mortgage or auto loan, do your rate shopping within a 14 to 45-day window -- FICO treats multiple inquiries of the same loan type in that window as a single inquiry.

Common Credit Score Myths

Myth: Checking your own credit hurts your score. Checking your own score is a soft inquiry and has zero effect. Check as often as you like through free tools like Credit Karma, your card issuer's app, or AnnualCreditReport.com.

Myth: Carrying a balance improves your score. This is flatly wrong. You gain no scoring benefit from paying interest. Pay your full statement balance every month. The bureau sees that you used credit and paid it back, which is all the positive signal you need.

Myth: Closing a credit card improves your score. Closing a card reduces your total available credit, which can increase utilization. It also eventually removes that account's age from your history. In most cases, keeping the card open is the better move.

Myth: Your income affects your credit score. Income does not appear in credit scoring models. A person earning $40,000 who pays every bill on time can have a higher score than someone earning $400,000 who misses payments.

Building a Plan

If you want to move your score up, focus on the high-impact factors first. Automate all minimum payments so you never miss one. Then work on getting utilization below 10%. Those two factors alone account for 65% of your score. The rest improves with patience and consistent behavior.

For a deeper look at cards that can help you build or rebuild credit, check out our best cards for beginners roundup or take our card recommendation quiz to find a match based on your current score.