FICO (Fair Isaac Corporation) scores are the most widely used credit scoring model among U.S. lenders, generally ranging from 300 to 850. While the exact proprietary formula isn't fully public, FICO has disclosed the general categories and their approximate weighting, which is useful for understanding what actually drives the number.

The five general factors

Payment history (roughly 35%)

The single largest factor — whether payments on credit accounts have been made on time. Late payments, collections, bankruptcies, and other negative marks in this category tend to have an outsized impact on the score, and their effect generally lessens over time as they age, even before they eventually fall off the report entirely.

Amounts owed (roughly 30%)

This category is largely driven by credit utilization, covered in depth in our dedicated guide, though it also factors in the total amount owed across all accounts and how many accounts carry a balance. This is the second-largest factor and, notably, one of the faster-moving ones, since it's recalculated based on current balances each reporting cycle.

Payment history and amounts owed together make up roughly two-thirds of a FICO score's weighting — meaning the two most impactful habits are paying on time and keeping balances low relative to limits.

Length of credit history (roughly 15%)

This considers the age of your oldest account, the age of your newest account, and the average age across all accounts. This is one of the factors that genuinely can't be rushed — it simply requires time, which is part of why closing an old, unused account can sometimes hurt a score more than expected, by lowering the average account age.

Credit mix (roughly 10%)

Having a mix of different credit types — credit cards, an auto loan, a mortgage — can modestly help a score, since it demonstrates experience managing different kinds of credit. This is a relatively minor factor and not a reason to take on debt specifically to diversify credit type.

New credit (roughly 10%)

Opening several new accounts in a short period, or generating multiple hard inquiries, can modestly and temporarily lower a score, since it can look like increased risk to a scoring model. A single hard inquiry typically has a small, short-lived impact; several in a short window have a more noticeable effect.

FICO vs. VantageScore

VantageScore is the other major scoring model used in the U.S., developed jointly by the three credit bureaus as an alternative to FICO. It uses a similar 300-850 range but weighs some factors slightly differently, which is part of why checking your "credit score" from different sources can show different numbers — both can be accurate under their respective models simultaneously.

Multiple FICO versions exist too

FICO itself has released many versions over the years (FICO 8, FICO 9, industry-specific versions for auto lending or mortgages), and different lenders may use different versions for different purposes — which is another reason the "same" credit score can appear to vary depending on where and when it's checked.

Try thisRather than fixating on a single score number from one source, focus on the underlying factors — payment history and utilization especially, since they make up roughly two-thirds of the calculation across most versions and models. Improving those two consistently improves virtually any version of a credit score you might be checked against.

Understanding the general FICO factor weighting doesn't require knowing the exact proprietary formula — the practical takeaway is consistent across nearly every credit scoring model: pay on time, every time, and keep balances low relative to available credit.