A credit score is a three-digit number that lenders use to estimate how likely you are to repay borrowed money on time. Most U.S. scores come from two model families, FICO and VantageScore, and both run from 300 to 850. The score is not stored in your file; it is calculated on demand from the information in your credit report at the moment a lender or app requests it. Because the underlying data changes constantly, your score is really a snapshot rather than a fixed grade.
What the score actually measures
A credit score is a statistical prediction of risk, specifically the odds that you will fall 90 or more days behind on a debt within the next couple of years. It is built only from information in your credit report, such as your accounts, balances, payment history, and inquiries. It deliberately ignores income, savings, job title, race, and age, because those are either barred by law or not predictive in the model. Higher numbers signal lower risk, which is why they unlock lower interest rates and better terms.
FICO versus VantageScore
FICO, created by the Fair Isaac Corporation, is the score most mortgage and card lenders rely on, and it exists in many versions such as FICO 8 and FICO 9. VantageScore was built jointly by the three credit bureaus and is common in free credit-monitoring apps. Both use the 300 to 850 range and weigh similar behaviors, but their formulas differ, so the same report can yield different numbers. This is normal and does not mean either score is wrong.
Why you have many different scores
There is no single official credit score. Each of the three bureaus, Equifax, Experian, and TransUnion, keeps its own file, and lenders do not all report to every bureau, so the data can differ. Layer several FICO and VantageScore versions on top of three sets of data and you can easily have dozens of valid scores at once. A lender may also use an industry-specific version, such as an auto or bankcard score tuned for that product.
Why your number moves
Scores recalculate every time your report is pulled, using whatever data is present that day. Paying down a card, a new balance being reported, opening or closing an account, or a payment aging past due can all nudge the number. Because most cards report your balance once a month around the statement date, your score often shifts on a monthly rhythm. Small movements of a few points are routine and usually not worth worrying about.
The score ranges lenders use
Although cutoffs vary by lender, FICO scores are commonly grouped as poor (300 to 579), fair (580 to 669), good (670 to 739), very good (740 to 799), and exceptional (800 to 850). Crossing into a higher band is what typically earns better pricing, so moving from 690 to 740 can matter more than moving from 740 to 790. Most lenders reserve their best advertised rates for applicants in the very good and exceptional tiers.
Suppose two apps show you a 712 and a 728 in the same week. One is likely a VantageScore built on Experian data and the other a FICO 8 built on TransUnion data. Both are legitimate; they simply use different formulas and slightly different files. A mortgage lender might pull yet another version and see 705.
Key takeaways
- Credit scores run from 300 to 850 and predict the odds you will fall seriously behind on a debt.
- They are calculated on demand from your credit report, not stored as a fixed number.
- FICO and VantageScore are different model families, and each bureau holds its own data, so you have many scores.
- Income, savings, and job title are not part of the score.
- Reaching a higher score band, not just a higher number, is what unlocks better rates.
Common mistakes
- Assuming there is one true score that every lender sees.
- Panicking over normal month-to-month swings of a handful of points.
- Believing that checking your own score lowers it, which it does not.
FAQ
Does checking my own credit score hurt it?
No. Viewing your own score is a soft inquiry and has no effect. Only a hard inquiry from a credit application can shave off a few points.
Why is my mortgage score lower than my app score?
Mortgage lenders often use older FICO versions and take the middle of three bureau scores, which can differ from the VantageScore shown in a free app.
What is a good credit score?
Generally, 670 and above is considered good on the FICO scale, and 740 and up unlocks the best pricing from most lenders.