The ranges: 300 to 850

Most scores (FICO and VantageScore) run from 300 to 850. Higher is better. Roughly: 300–579 is poor, 580–669 fair, 670–739 good, 740–799 very good, and 800+ excellent. You don't need 850 to get approved for good things; from about 700 you already have solid options.

How your score is calculated

It's five factors with different weights: your payment history (the biggest, ~35%), how much of your limit you use (~30%), how old your credit is (~15%), how many new accounts/recent applications you have (~10%), and the variety of your accounts (~10%). Paying on time and using little of your limit is over half the score.

Why you have several scores

You don't have just one score. There are two main models (FICO and VantageScore) and three bureaus (Experian, Equifax, TransUnion), so the number changes with who calculates it and from what data. That's why the score in an app may not exactly match the one a lender uses. Don't sweat the exact difference; watch the trend.

What does NOT affect your score

Your income isn't in your score. Neither is your immigration status. Having an ITIN instead of an SSN doesn't give you a lower score. And checking your own credit never lowers it — that's a “soft inquiry.” What lowers your score is late payments, owing too much, and many new applications in a short time.

How to start if you have no score

If you've never had credit, you don't have a “bad” score: you're credit-invisible, which also closes doors. The fix is opening one or two accounts that report: a secured card, a credit-builder loan, or reporting your rent. With on-time money for a few months, you go from no score to a starting one.

Check yours, free

Pull your credit report free at annualcreditreport.com — it's a federal right, no cost. That's where you see what accounts you have and whether there are errors. Knowing where you stand is the first step to improving.