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, landlords, insurers, and even some employers use it to make decisions about you. The difference between a good score and a mediocre one can cost you tens of thousands of dollars over your lifetime, or determine whether you get approved at all.
How a Credit Score Is Calculated
Two major scoring models dominate: FICO and VantageScore. Both pull from the same underlying data in your credit reports, but they weigh the factors slightly differently. Here’s what goes into the number:
- Payment history (35%–40% of your score): Whether you’ve paid your bills on time. This is the single biggest factor. Even one payment that’s 30 or more days late can drag your score down significantly, and the damage gets worse the longer a payment goes unpaid.
- Credit utilization (about 20%–30%): How much of your available credit you’re actually using. If you have a credit card with a $10,000 limit and you’re carrying a $7,000 balance, that 70% utilization ratio hurts your score. Keeping it below 30% is a common guideline, and below 10% is even better.
- Length of credit history (15%–21%): How long your accounts have been open. A longer track record gives scoring models more data to judge you by, which generally helps.
- Credit mix (about 10%): Having different types of credit, like a credit card, an auto loan, and a mortgage, shows you can manage various kinds of debt.
- New credit inquiries (about 10%): Applying for several new accounts in a short window can signal financial stress. Each “hard inquiry” from a lender may lower your score by a few points temporarily.
Payment history and utilization together account for roughly two-thirds of your score. If you do nothing else, paying on time and keeping your balances low will have the biggest impact.
What the Score Ranges Mean
FICO scores break down into general tiers that lenders use as shorthand for your risk level. The exact cutoffs vary slightly between lenders, but the widely accepted categories look like this:
- 800–850 (Exceptional): You’ll qualify for the best rates and terms available.
- 740–799 (Very Good): Still gets you excellent offers from most lenders.
- 670–739 (Good): You’re considered a reliable borrower and will qualify for most products, though not always at the lowest rates.
- 580–669 (Fair): You can still get approved for credit, but expect higher interest rates and less favorable terms.
- 300–579 (Poor): Approval is difficult. You may need secured credit cards or loans with a co-signer to start rebuilding.
A score of 670 or above is generally where doors start opening without much friction. Below that, every financial product you apply for gets more expensive.
How Your Score Affects Borrowing Costs
The financial gap between credit tiers is not abstract. Consider a real example using mortgage data from the Consumer Financial Protection Bureau. On a $400,000 home with 10% down and a 30-year fixed conventional loan, a borrower with a 625 credit score could see interest rates as high as 8.875%. A borrower with a 700 score could get offers as low as 5.875%.
Over 30 years, that difference adds up to as much as $264,523 in extra interest for the lower-score borrower. Even in just the first five years, the gap can be over $50,000. On the same house, with the same income, the person with the lower credit score pays a quarter of a million dollars more simply because of a 75-point difference in their score.
The pattern holds for auto loans, personal loans, and credit cards too. A lower score means a higher interest rate on every dollar you borrow. Credit card APRs for someone with fair credit can run 8 to 10 percentage points higher than the rates offered to someone with excellent credit, which translates to hundreds of dollars a year if you carry a balance.
Where Credit Scores Show Up Beyond Loans
Your credit score doesn’t just matter when you’re borrowing money. It quietly shapes several other parts of your financial life.
Landlords routinely check credit when you apply for an apartment. A low score can mean a denied application or a requirement to pay several months’ rent upfront as a deposit. Utility companies also check your credit when you set up service. If your score is low, they may require a security deposit before turning on electricity, gas, or water.
Insurance companies in most states use credit-based insurance scores when setting your premiums for auto and homeowners coverage. A lower score can mean noticeably higher premiums, even if your driving record is clean. Some employers check a version of your credit report during the hiring process, particularly for roles that involve handling money or sensitive financial data. They don’t see your actual score, but they can review your credit history for red flags like collections or bankruptcies.
The good news: these non-lending checks are considered “soft inquiries,” meaning they don’t affect your score at all. But the information in your report still influences the decisions these companies make about you.
How to Build and Improve Your Score
If you’re starting from scratch or trying to recover from past mistakes, the fundamentals are straightforward.
Pay every bill on time, every month. Set up autopay for at least the minimum payment on all your accounts so you never accidentally miss a due date. Since payment history is the largest factor in your score, even a few months of consistent on-time payments starts moving the needle.
Reduce your credit card balances. If you’re carrying high balances relative to your limits, paying them down will improve your utilization ratio, often within a single billing cycle. This is one of the fastest ways to see a score increase. If you can’t pay down balances quickly, you can also call your card issuer and request a credit limit increase, which lowers your utilization ratio without requiring you to pay anything extra.
Keep old accounts open. Closing a credit card you’ve had for years shortens your average account age and reduces your total available credit, both of which can lower your score. Even if you don’t use the card much, keeping it open and making a small purchase every few months helps.
Space out new credit applications. Every hard inquiry costs you a few points, and clustering several applications together looks risky to scoring models. If you’re rate-shopping for a mortgage or auto loan, do it within a focused window of about two weeks. The scoring models recognize this pattern and typically count multiple inquiries for the same type of loan as a single inquiry.
Check your credit reports for errors. You can pull your reports for free at AnnualCreditReport.com from each of the three major bureaus: Equifax, Experian, and TransUnion. Look for accounts you don’t recognize, incorrect balances, or late payments that were actually made on time. Disputing and removing errors can produce an immediate score improvement.
How Long Changes Take to Show Up
Credit scores don’t update in real time. Your lenders and creditors report your account activity to the bureaus on their own schedules, usually once a month. After they report, it can take a few days for the new information to appear in your credit file and affect your score.
Positive changes like paying down a balance can show up within one to two billing cycles. Negative marks take much longer to fade. A late payment stays on your report for seven years, though its impact on your score diminishes over time. A bankruptcy can remain for seven to ten years depending on the type. Collections accounts also stick around for seven years from the date of the original missed payment that led to the collection.
The most important thing to understand is that your credit score is a moving target. It reflects your financial behavior over time, and it responds to changes in that behavior. Even if your score is low today, consistent habits over 6 to 12 months can produce meaningful improvement.