A three-digit number can decide whether you get approved for an apartment, what interest rate you pay on a car loan, or whether a landlord even calls you back. Yet most people have only a vague sense of how your credit score actually works. Here is what a credit score is built from and how it is calculated.
What a Credit Score Actually Is, and How It Works
A credit score is a number, typically ranging from 300 to 850, meant to summarize how likely you are to repay borrowed money based on your credit history. The most widely used scoring model is the FICO Score, developed by the Fair Isaac Corporation, though VantageScore is a common alternative. Lenders, landlords, and sometimes employers use these scores to quickly assess risk before extending credit or entering into an agreement, rather than digging through a full credit report themselves.
Where the Number Comes From
Your score is not pulled from thin air; it is calculated from the credit report maintained by one of the three major credit bureaus, Equifax, Experian, and TransUnion, each of which independently tracks your borrowing and repayment activity reported by lenders. Because each bureau may have slightly different information on file, your score can vary somewhat depending on which bureau’s data was used to calculate it.
The Five Ingredients, and How Much Each One Counts
According to myFICO, the company’s scoring formula weighs five categories. Payment history carries the most weight at 35%, reflecting whether you have paid past credit accounts on time. Amounts owed follows at 30%, largely driven by your credit utilization, how much of your available credit you are actually using. Length of credit history accounts for 15%, rewarding accounts that have been open and in good standing for longer. New credit makes up 10%, capturing recent applications and newly opened accounts. And credit mix, the variety of account types you manage, such as credit cards, auto loans, and mortgages, rounds out the final 10%.
Why Utilization Matters So Much
Because amounts owed is the second-largest factor, credit utilization deserves special attention. This is the percentage of your available credit that you are currently using across all your accounts, and running that number high, even if you pay your bill in full every month, can drag your score down, because scoring models see it as a sign of financial strain. Keeping balances low relative to your credit limits, and paying on time every cycle, are the two most reliable levers most people have to influence their own score.
Why It Matters Beyond a Single Number
A higher credit score generally translates into lower interest rates and better terms on loans, credit cards, and even insurance premiums in some states, which can add up to real savings over the life of a loan. The Consumer Financial Protection Bureau notes that people are entitled to free copies of their credit reports, allowing them to check the underlying data behind their score and dispute errors, since mistakes on a credit report can drag a score down through no fault of the consumer.