What Is a Credit Score and How Is It Calculated?
A three-digit number, built from five weighted ingredients, that quietly decides whether you get approved and what you’ll pay for it.
What the number actually represents
A credit score is a prediction of how likely you are to repay borrowed money on time, based entirely on the information in your credit reports. It’s not a measure of your income, your savings, or your overall wealth; it’s narrowly focused on your history of borrowing and repaying. Most widely used credit scores, including FICO scores, range from 300 to 850, with higher scores generally signaling lower risk to a lender.
You don’t have just one credit score. Different scoring models, different credit bureaus, and even different points in time can all produce slightly different numbers for the same person, which is why the score a lender pulls might not exactly match a score you saw somewhere else.
The five factors, and roughly how much each counts
FICO, the most widely used scoring model, has disclosed the general categories that go into its calculation, along with their approximate weight. Payment history carries the most weight, around 35%, reflecting whether you’ve paid bills on time or missed payments, had accounts sent to collections, or filed for bankruptcy. Amounts owed comes next, around 30%, which largely reflects your credit utilization, how much of your available credit you’re actually using.
Length of credit history accounts for roughly 15%, rewarding accounts that have been open and in good standing for a longer time. New credit makes up about 10%, reflecting recently opened accounts and recent credit inquiries. Credit mix accounts for the final 10%, reflecting whether you have experience managing different types of credit, like a mix of credit cards and installment loans, rather than only one type.
These weights are approximate and can shift slightly between different FICO score versions, and other scoring models, like VantageScore, use a somewhat different weighting scheme entirely, though the same broad categories, payment history and credit usage chief among them, tend to dominate across nearly every model in use.
Why credit utilization matters so much
Credit utilization, the percentage of your available revolving credit currently in use, is one of the more heavily weighted individual factors within the “amounts owed” category. A cardholder with a $10,000 total credit limit carrying a $2,000 balance has a 20% utilization ratio; the same $2,000 balance on a $4,000 limit produces a 50% utilization ratio, a meaningfully worse signal even though the dollar amount owed is identical.
This is why paying down balances, or requesting a credit limit increase without adding new spending, can improve a score relatively quickly compared to other factors like length of credit history, which can only improve gradually over time no matter what action you take. Utilization is typically calculated both per card and across all your revolving accounts combined, so a single maxed-out card can drag down your overall utilization ratio even if your other cards carry low balances.
Credit report versus credit score
A credit report and a credit score are related but different things. Your credit report is a detailed record of your credit accounts, payment history, and inquiries, maintained by credit bureaus like Equifax, Experian, and TransUnion. Your credit score is a number calculated from the information in that report. Errors on your credit report, an account that isn’t actually yours, an incorrect late payment, can unnecessarily drag your score down, which is why checking your credit report periodically for accuracy matters as much as monitoring the score itself.
You’re entitled to a free copy of your credit report from each of the three major bureaus on a regular basis through AnnualCreditReport.com, the only source authorized by federal law to provide these free reports. Disputing a genuine error is a formal process handled directly with the credit bureau reporting the inaccurate information, and bureaus are required to investigate disputes within a set timeframe once they’re filed.
Where your score actually gets used
Lenders use credit scores to decide whether to approve a mortgage, auto loan, or credit card application, and the specific interest rate or credit limit offered. Beyond traditional lending, landlords often check credit as part of a rental application, and some insurance companies use credit-based information to help set premiums, sometimes called an insurance score, which draws on similar underlying data but isn’t identical to a standard credit score.
Even employers sometimes review a modified version of a credit report, though not a numeric score, as part of a background check for certain positions, particularly roles involving financial responsibility. This use is more restricted than lending decisions and typically requires your explicit consent under federal law.
Why the exact formula stays private
FICO has never disclosed its exact scoring algorithm, only the general categories and their approximate weights. This means no one, not even financial advisors, can tell you with certainty exactly how many points a specific action will add or subtract from your score. What’s well understood, from FICO’s own disclosures and from broad patterns observed across scoring models, is which general behaviors tend to help and which tend to hurt, even without an exact point value attached to each one.
This uncertainty is part of why generic advice like “pay your bills on time” and “keep balances low” tends to work reliably across virtually every scoring model, even without an exact formula: those behaviors sit inside the two most heavily weighted categories regardless of the specific model’s undisclosed internal math.
Watch how your other numbers connect
Your credit score directly affects the interest rates you’re offered on loans and credit cards, which in turn affects your actual monthly payments and total interest costs. Our Credit Card Payoff Calculator and APR Calculator can help you see how a given rate translates into real dollar costs, whatever your current credit profile looks like.
Common questions about credit scores
On the common 300-850 scale, scores above roughly 670 are generally considered good, above 740 very good, and above 800 exceptional, though specific thresholds for “good enough” vary by lender and loan type.
Different scoring models, different credit bureaus supplying the underlying data, and the exact date a score is calculated can all produce slightly different results, even for the same person on the same day.
No. Checking your own score or report is considered a “soft inquiry” and does not affect your credit score. Only “hard inquiries,” typically triggered when you formally apply for new credit, can have a small, temporary effect on your score.
Credit scores are typically recalculated whenever new information is reported to the credit bureaus, which for most accounts happens roughly monthly, though the exact timing can vary by lender and account type.
On the common 300-850 scale, scores above roughly 670 are generally considered good, above 740 very good, and above 800 exceptional.
Different scoring models, different credit bureaus, and even the exact date a score is calculated can all produce slightly different results for the same person.
No. Checking your own score is a “soft inquiry” and doesn’t affect your score. Only “hard inquiries,” triggered by formally applying for new credit, can have a small, temporary effect.
Credit scores are typically recalculated whenever new information is reported to the credit bureaus, which for most accounts happens roughly monthly.