A credit score is a three-digit number, typically ranging from 300 to 850, that represents how likely you are to repay borrowed money. Lenders use it to decide whether to approve you for credit cards, mortgages, auto loans, and other forms of borrowing, and what interest rate to charge you. The score is generated by a mathematical model that analyzes the information in your credit report, weighting some behaviors more heavily than others.
Where Credit Scores Come From
Your credit score is built from data in your credit report, which is maintained by three major credit bureaus: Equifax, TransUnion, and Experian. These bureaus don’t generate the data themselves. Instead, your lenders, credit card issuers, and other creditors report your account activity to them on a regular basis.
For each account, creditors typically report the type of credit (mortgage, auto loan, credit card), your credit limit or original loan amount, your current balance, your payment history including whether you’ve paid on time, and the dates the account was opened and closed. They also report whether an account is delinquent or has been sent to collections, and whether it’s an individual or joint account.
Beyond your active accounts, your credit report includes public records like bankruptcies, plus a list of inquiries showing which companies have pulled your report. It also carries identifying information: your name, address, Social Security number, and date of birth. All of this feeds into the scoring model.
The Five Factors Behind Your Score
The most widely used scoring model is the FICO Score, and it groups your credit data into five categories, each carrying a specific weight.
- Payment history (35%) — This is the single biggest factor. It tracks whether you’ve paid your bills on time across all your accounts. Late payments, accounts sent to collections, and bankruptcies all drag this category down. A single 30-day late payment can drop your score significantly, and the damage increases the longer the payment goes unpaid.
- Amounts owed (30%) — This measures how much of your available credit you’re currently using, often called your credit utilization ratio. If you have a credit card with a $10,000 limit and carry a $3,000 balance, your utilization on that card is 30%. Lower utilization signals to lenders that you’re not overextended. Keeping utilization below 30% is a common guideline, but people with the highest scores tend to use far less than that.
- Length of credit history (15%) — Longer credit histories generally produce higher scores. This factor considers the age of your oldest account, the age of your newest account, and the average age across all accounts. Closing an old credit card can shorten your average account age and potentially lower your score.
- New credit (10%) — Each time you apply for a loan or credit card, the lender pulls your credit report, creating what’s called a hard inquiry. A few inquiries won’t hurt much, but a cluster of applications in a short period can signal financial stress. Hard inquiries stay on your report for two years, though their scoring impact fades within a few months. Rate shopping for a mortgage or auto loan within a focused window (typically 14 to 45 days, depending on the scoring model) counts as a single inquiry.
- Credit mix (10%) — This rewards you for managing different types of credit successfully. Having a mix of revolving credit (like credit cards) and installment loans (like a mortgage or car loan) can help your score. That said, this is the smallest factor, and opening accounts you don’t need just to diversify your mix isn’t worth it.
Why Your Score Differs Across Bureaus
You don’t have just one credit score. You have several. Not all creditors report to all three bureaus, so the information at Equifax, TransUnion, and Experian may not be identical. A credit card issuer might report to two bureaus but not the third, meaning your report at each bureau could show slightly different balances, accounts, or payment records.
On top of that, different scoring models can produce different numbers from the same data. FICO alone has multiple versions (FICO 8, FICO 9, FICO 10), and VantageScore is another widely used model. Mortgage lenders, auto lenders, and credit card issuers may each use a different version tailored to their industry. A 20- to 40-point difference between your scores at different bureaus is completely normal.
What Your Score Costs You in Real Dollars
The gap between a good score and a mediocre one translates directly into money. Consider a 30-year fixed-rate mortgage on a $400,000 home with a 10% down payment. Based on April 2025 rate data from the CFPB, a borrower with a 700 credit score could see offers as low as 5.875%, while someone with a 625 score might face rates up to 8.875%.
The difference in total interest paid over 30 years between those two scenarios: up to $264,523. That’s effectively the price of a second house, paid entirely in interest, because of a 75-point gap in credit scores. Higher scores also give you more lenders to choose from, which means more bargaining power and better loan terms overall.
What Doesn’t Affect Your Score
Your credit score ignores your income, employment status, savings, and investment accounts. A person earning $40,000 a year who pays every bill on time can have a higher score than someone earning $400,000 who misses payments. Your race, religion, gender, marital status, and age are also excluded by law. Checking your own credit report (a soft inquiry) has no impact on your score either.
Rent and utility payments historically haven’t appeared on credit reports unless they went to collections, though some newer services now allow you to opt in to having on-time rent payments reported. Medical debt has a complicated relationship with credit reporting. While a federal rule attempted to remove medical bills from credit reports, that rule was vacated by a court in July 2025 after being found to exceed the CFPB’s statutory authority. Medical debt can still appear on your report, though coded medical information cannot identify your specific provider or the nature of services received.
How to Build and Protect Your Score
Because payment history and amounts owed together account for 65% of your FICO Score, the two highest-impact habits are straightforward: pay every bill on time and keep your credit card balances low relative to your limits. Setting up autopay for at least the minimum payment eliminates the risk of accidentally missing a due date.
If you’re building credit from scratch, a secured credit card (where you put down a deposit that serves as your credit limit) or becoming an authorized user on a family member’s card can establish your first trade line. Once you have active accounts, time works in your favor. The length-of-history factor rewards patience, so keeping older accounts open, even if you rarely use them, helps your average account age.
Checking your own credit reports regularly lets you catch errors before they cause damage. You’re entitled to free weekly reports from all three bureaus through AnnualCreditReport.com. Disputes over inaccurate information, like a payment incorrectly marked late or an account you don’t recognize, can be filed directly with the bureau reporting the error. Correcting mistakes is one of the fastest ways to see a score improvement.