How Credit Scores Are Calculated: The 5 Factors That Determine Your FICO Score

A FICO credit score ranges from 300 to 850, and it is calculated using five weighted factors. Each factor carries a different level of influence over your final score, and knowing where to focus your effort can mean the difference between a gradual climb and a dramatic improvement. Below, we break down each of the five factors and explain how ByeBadCredit's AI-powered dispute system addresses the ones that matter most.

1. Payment History (35%)

Payment history is the single most important factor in your credit score, accounting for 35% of the total. Lenders want to see that you consistently pay your bills on time. Late payments, missed payments, collections, charge-offs, and public records like bankruptcies or foreclosures all drag your score down significantly. Even a single 30-day late payment can cause a noticeable drop. This is also the factor that credit repair addresses most directly — many negative payment-history items are reported inaccurately, are outdated, or cannot be verified by the bureau, making them legally disputable under the Fair Credit Reporting Act (FCRA). ByeBadCredit's dispute system prioritizes these items because removing even one inaccurate late payment can produce a meaningful score increase.

2. Credit Utilization (30%)

Credit utilization measures how much of your available credit you are currently using. It is calculated by dividing your total balances by your total credit limits across all revolving accounts (credit cards, lines of credit). Experts recommend keeping utilization below 30%, and ideally below 10%, for the best scores. For example, if you have $10,000 in total credit limits, you should aim to carry less than $3,000 in balances — and ideally under $1,000. High utilization signals to lenders that you may be overextended. Unlike payment history, utilization can be improved quickly by paying down balances or requesting credit limit increases, which is why it is one of the fastest levers for boosting a score alongside a dispute campaign.

3. Length of Credit History (15%)

The length of your credit history contributes 15% of your score and considers the age of your oldest account, the average age of all your accounts, and how long it has been since you used each account. A longer credit history generally produces a higher score because it gives lenders more data to evaluate your behavior. This is why closing old credit cards can sometimes hurt your score — it shortens your average account age and reduces your total available credit. When rebuilding credit, it is wise to keep your oldest accounts open and active, even with small, occasional purchases that you pay off immediately.

4. Credit Mix (10%)

Credit mix accounts for 10% of your score and rewards borrowers who demonstrate they can manage different types of credit responsibly — for example, a combination of revolving accounts (credit cards) and installment loans (auto loans, mortgages, student loans). Lenders view a healthy mix as evidence that you can handle varied financial obligations. You should not take on new debt solely to improve your mix, but as you naturally add different credit types over time, this factor can provide a modest boost to your overall score.

5. New Credit and Inquiries (10%)

The final 10% relates to new credit activity, including recent hard inquiries and newly opened accounts. Each hard inquiry — triggered when a lender pulls your credit after you apply for a card or loan — can lower your score by a few points and remains on your report for two years. Opening several new accounts in a short period signals higher risk to lenders. Importantly, hard inquiries you did not authorize (often resulting from identity theft or clerical errors) are disputable. ByeBadCredit disputes unauthorized inquiries as part of its comprehensive credit repair process, helping remove items that unfairly penalize your score.

Putting It All Together

Payment history and credit utilization together determine 65% of your credit score, so they should be your primary focus. Credit repair directly targets the negative items weighing down your payment history, while smart utilization management provides an immediate secondary boost. When combined with a healthy credit mix, a long account history, and disciplined new-credit behavior, these strategies form a complete roadmap to a strong, lasting credit score — and a more secure financial future.