Your credit score is not assigned by some central authority. It is calculated on demand by a software model that reads the information in your credit report and predicts how likely you are to repay borrowed money on time. Different models exist, and the same person can have many different scores at once. Below is how the most common models actually work, what moves the number, and which parts you can control.
What a credit score is trying to predict
A credit score is a snapshot estimate of risk. It is built to answer one narrow question for a lender: based on how this person has handled credit so far, how likely are they to fall seriously behind on a new debt? That is it. It does not measure your income, your savings, your character, or whether you are a responsible person. It only summarizes patterns in your credit report, so the number is only as accurate as the data feeding it -- which is why checking your reports for errors matters.
The two main models: FICO and VantageScore
There are two dominant scoring brands. FICO is the older one and is used in the large majority of lending decisions, especially mortgages, auto loans, and credit cards. VantageScore was created by the three major credit bureaus and shows up often in the free scores that banking apps and websites display. Both use a 300 to 850 range, and both read the same kind of credit-report data, but they weigh it differently, so the two numbers rarely match exactly.
It helps to remember that there is no single "your score." There are three credit bureaus (Equifax, Experian, and TransUnion), multiple models, and several versions of each model still in use. That means dozens of valid scores can exist for you at the same moment. A small difference between two numbers is normal and usually not worth worrying about.
The five FICO factors and their approximate weights
FICO publicly describes five categories that go into a score. The weights below are approximate and can shift depending on what is in an individual report, but they give you a reliable sense of what matters most:
- Payment history -- about 35%. Whether you pay on time. This is the single most important factor. Late payments, collections, charge-offs, and bankruptcies all live here, and a missed payment carries a lot of weight.
- Amounts owed and credit utilization -- about 30%. How much you owe, and especially how much of your available revolving credit you are using. Carrying balances close to your limits tends to weigh you down. See what credit utilization is for the details on this one.
- Length of credit history -- about 15%. How long your accounts have been open, including the age of your oldest account and the average age of all of them.
- Credit mix -- about 10%. Whether you have experience with different types of credit, such as credit cards alongside an installment loan.
- New credit and inquiries -- about 10%. Recently opened accounts and recent applications for credit, which create hard inquiries.
Notice that the first two factors together make up roughly two-thirds of the score. We will come back to why that matters.
How VantageScore weighs things
VantageScore uses similar inputs but describes them qualitatively rather than publishing fixed percentages for its current versions. In broad terms, payment history is described as extremely influential; the age and type of your credit along with your utilization are described as highly influential; the total amount you owe and recent credit behavior carry meaningful weight; and available credit has a smaller role. The practical upshot is the same as with FICO: paying on time and keeping balances low are what move the needle most.
Commonly cited score bands and how you become scoreable
You do not "start" with a score of zero or 300. Until your credit report shows enough activity, you simply are not scoreable. Generally you need roughly three to six months of reported account activity before a score can be generated at all.
Once you have a score, lenders often sort numbers into tiers. These are commonly cited ranges, not a law, and individual lenders set their own cutoffs:
- Poor: below about 580
- Fair: about 580 to 669
- Good: about 670 to 739
- Very Good: about 740 to 799
- Exceptional: about 800 and up
How to see your reports and scores for free
You can pull your credit reports from all three bureaus for free at annualcreditreport.com, which is the official source. Note that those are your reports -- the underlying data -- not your scores. To see an actual score for free, many credit card issuers and banking apps now show one (often a FICO or VantageScore) right in your account. Reviewing both is worthwhile: errors on a report can drag a score down, and you cannot fix what you have not looked at.
The practical takeaway
If you only remember one thing, make it this: the two biggest levers you actually control are paying on time (about 35% of FICO) and keeping utilization low (about 30%). Those two habits drive most of what you can influence, and they cost nothing. Results vary by person and model, and no honest source can promise an exact number of points any single action will add or remove. If you want to dig into the moves that help, see whether paying off debt helps your score and the free, do-it-yourself approach in how to repair your credit yourself. You can also map out how long items linger using the credit report timeline tool, and if you would rather talk to a person, a nonprofit counselor through the NFCC can review your situation at low or no cost.
This page is general information, not financial or legal advice. Credit-scoring models vary — consider talking to a nonprofit credit counselor before you act.