How Is a Credit Score Calculated?

Your credit score is a three-digit number, usually between 300 and 850, that lenders use to guess how likely you are to pay back borrowed money. It is calculated by a formula that weighs five main factors: payment history, amounts owed, length of credit history, new credit, and credit mix. The two most common scoring models are FICO and VantageScore, and both use similar ingredients but with different weights.

This guide explains each factor, shows you a step-by-step example, and clears up common mistakes. For a deeper look at how scores affect loans and cards, see our credit score hub.

What is a credit score?

A credit score is a snapshot of your credit report, which is a record of your borrowing history. Lenders, landlords, and even some insurance companies use it to decide whether to work with you and at what price. A higher score usually means lower risk to lenders, which can lead to better interest rates and higher approval odds. A lower score can make borrowing more expensive or harder to get.

Your score is not stored in a single national database. Instead, three major credit bureaus (Equifax, Experian, and TransUnion) each keep a credit report on you. Scoring models like FICO and VantageScore read those reports and turn them into a number. Because the reports can differ slightly, your score may vary from bureau to bureau.

The five factors and their weights

FICO, the most widely used scoring model, breaks down the calculation like this:

VantageScore uses similar categories but weights them differently, and it treats things like utility payments slightly differently. The exact formula is secret, but these five areas are the building blocks.

Payment history: the biggest piece

Payment history is the most important factor because it shows lenders whether you actually pay what you owe. A single late payment can stay on your credit report for up to seven years and can lower your score noticeably. On-time payments, on the other hand, build a positive track record over time.

What counts as a late payment? Usually a payment is not reported as late until it is at least 30 days past due. But even a payment that is a few days late can trigger a late fee, so it is best to pay by the due date. Bankruptcies and foreclosures are also part of payment history and can hurt your score for years.

Amounts owed and credit utilization

Amounts owed is the second-biggest factor. The key measure here is credit utilization, which is the percentage of your available credit that you are using. For example, if you have a credit card with a $1,000 limit and you carry a $500 balance, your utilization is 50%. Scoring models look at both per-card and overall utilization.

Lower utilization is generally better. People with the highest scores often keep utilization under 10%, and staying under 30% is a common guideline. Even if you pay your balance in full every month, your issuer may report your balance to the bureau at the end of your statement period, so a high balance at that moment can raise your utilization temporarily.

Length of credit history, new credit, and credit mix

The age of your credit matters because lenders like to see a long track record. The formula looks at the age of your oldest account, your newest account, and the average age of all your accounts. Closing an old account can shorten your average history, which is one reason it is often better to keep old cards open, even if you do not use them often.

New credit refers to recent applications and openings. Each time you apply for credit, a hard inquiry appears on your report and can shave a few points off your score. Multiple inquiries in a short time can signal risk, though rate shopping for a single loan (like a mortgage) is usually treated as one inquiry if done within a short window.

Credit mix is the variety of credit types you have. Having both revolving credit (like a credit card) and installment credit (like a car loan) can help, but you do not need to open new accounts just to improve this factor.

Worked example: How one balance change moves a score

Let us look at a realistic example. Meet Priya, who has three credit cards and one student loan. Her total credit limit across the cards is $10,000. She currently carries balances of $2,000 on Card A, $1,500 on Card B, and $500 on Card C. Her total balance is $4,000, so her overall utilization is 40% ($4,000 ÷ $10,000 = 0.40, or 40%).

Priya pays down her balances by $1,500, bringing her total to $2,500. Now her utilization is 25% ($2,500 ÷ $10,000 = 0.25). That drop from 40% to 25% could move her score up by 20 to 30 points, depending on the rest of her report. If she pays down another $1,000, her utilization falls to 15% ($1,500 ÷ $10,000 = 0.15), which may push her into a higher score band.

The table below shows the math:

Note that these score changes are estimates. The actual effect depends on your whole credit profile, but the direction is clear: lower utilization tends to help your score.

What people get wrong about credit scores

Mistake 1: Checking your own credit lowers your score. That is false. When you check your own credit, it is a soft inquiry and does not affect your score. Only hard inquiries from lenders when you apply for credit can lower it, and even then usually by a few points.

Mistake 2: Closing a credit card always helps your score. Closing a card reduces your total available credit, which can raise your utilization if you carry balances on other cards. For example, if you have $5,000 in limits and a $1,000 balance, your utilization is 20%. If you close a card with a $2,000 limit, your available credit drops to $3,000, and your utilization jumps to 33% ($1,000 ÷ $3,000). That can hurt your score.

Mistake 3: Carrying a small balance month to month helps your score. Some people think you need to pay interest to build credit. That is not true. Paying your balance in full by the due date builds a positive payment history without costing you interest. Carrying a balance only increases your utilization and adds interest charges.

Mistake 4: Your credit score is the same everywhere. Different bureaus and different scoring models can give you different numbers. A lender might use a FICO score based on your Equifax report, while another uses a VantageScore based on your TransUnion report. That is why your score can vary by a few points or more depending on where you check it.

Putting it together

Your credit score is a mathematical summary of your borrowing behavior, built from payment history, amounts owed, history length, new credit, and credit mix. The biggest levers are paying on time and keeping credit utilization low. Your score is not permanent; it changes as your credit report changes, so understanding how it works gives you a clearer picture of what moves it up or down.