Your credit score is a three-digit number that lenders use to estimate how likely you are to repay borrowed money on time. In the US, most scores fall between 300 and 850, and the two models that matter most are FICO and VantageScore. Understanding how credit scores are calculated helps you focus your efforts on the behaviors that actually move the number, rather than guessing at what might help.
Below is a breakdown of the factors both major models use, how much each one typically counts, and what you can do to strengthen your profile over time.
What Goes Into a Credit Score
Credit scoring models pull information from your credit reports at the three nationwide credit bureaus: Equifax, Experian, and TransUnion. They do not look at your income, your bank account balances, or your job title. Instead, they analyze the history of how you have handled credit and loans.
FICO, the model used by the vast majority of lenders for mortgage, auto, and card decisions, groups the data into five categories. The approximate weights for the base FICO Score are:
- Payment history (35%): Whether you have paid on time, plus any collections, bankruptcies, or delinquencies.
- Amounts owed (30%): How much credit you are using relative to your limits, often called credit utilization.
- Length of credit history (15%): How long your accounts have been open and how long since you last used them.
- New credit (10%): Recent applications and newly opened accounts.
- Credit mix (10%): A blend of revolving accounts like credit cards and installment loans like auto or student loans.
VantageScore, developed by the three bureaus jointly, uses a similar set of inputs but assigns somewhat different weights. In its newer models, payment history remains the single largest factor, followed by credit utilization and the balance of available credit. VantageScore is widely used for free consumer score services and by some lenders, so it is worth knowing that your FICO and VantageScore numbers can differ by a few points or more.
Payment History: The Single Biggest Factor
Payment history carries the most weight in nearly every model. A single 30-day late payment can stay on your report for up to seven years, though its impact fades as the account ages and you build a clean record afterward. Recent delinquencies hurt more than older ones.
Lenders typically report to the bureaus once a month. If you miss a due date, you usually have until the next reporting cycle before the late payment appears, and many issuers will not report a payment as late until it is 30 days past due. Setting up automatic payments for at least the minimum amount is one of the simplest ways to protect this category.
Bankruptcies, foreclosures, and accounts sent to collections also fall under payment history and can weigh on your score for years. Chapter 7 bankruptcies, for example, can remain on a credit report for up to 10 years.
Credit Utilization and Amounts Owed
Credit utilization is the percentage of your available revolving credit that you are using. If you have a $5,000 limit across your cards and a $1,500 balance, your utilization is 30%. Scoring models generally reward lower utilization, and consumers with the strongest scores often keep it below 10% to 30%.
Two important details:
- Utilization is calculated both per card and across all cards, so maxing out one card can hurt even if your overall usage is low.
- Issuers typically report balances at your statement closing date, not your due date. Paying down a balance before the statement closes can lower the utilization that gets reported.
Because utilization has no memory in most FICO models, paying down balances can produce a relatively quick score improvement once the new balance is reported.
Length of History, New Credit, and Credit Mix
The remaining factors are smaller but still meaningful, especially for people with thin files.
Length of credit history considers the age of your oldest account, the average age of all accounts, and how recently you opened or used accounts. Closing your oldest card can shorten your history and reduce your available credit, which may raise utilization.
New credit looks at hard inquiries, which occur when a lender checks your report for a credit application. A single inquiry usually has a modest effect, and FICO generally treats multiple mortgage or auto inquiries within a short window as one inquiry for scoring purposes. Opening several new accounts in a short period, however, can signal risk to lenders.
Credit mix rewards a track record with both revolving and installment credit. You do not need every type of loan, and opening debt just to diversify is rarely wise, but a healthy mix can help at the margin.
How to Use This Information
Because the weights are known, you can prioritize. Focus first on paying every bill on time, then on keeping card balances low relative to limits. Check your credit reports at AnnualCreditReport.com for errors, since inaccuracies can drag down your score and disputing them is free. Avoid unnecessary hard inquiries before a major loan application, and be patient with length-of-history factors, which improve naturally over time.
Also remember that scores vary by model and by bureau. A score from one source is a snapshot, not a universal number, and lenders may use industry-specific versions such as FICO Auto Score or FICO Bankcard Score. Monitoring a consistent source helps you track direction rather than obsess over a single point.
What to Remember
Credit scores are calculated from the information in your credit reports, with payment history and amounts owed doing most of the work. Paying on time, keeping utilization low, maintaining older accounts, and applying for credit sparingly are the levers that matter most. Check your reports regularly, correct errors, and give the length-of-history factor time to work in your favor.
