Most college students can tell you their grade-point averages, or at least come close. But there's another number, a financial grade, that they probably don't know - but should.

That grade is a credit score, used by lenders and credit card companies to decide whether to lend you money and at what interest rate. Most look at the FICO score, created by Fair Isaac Corp. of Minneapolis.

The score ranges from 300 to 850 - the higher the better. It's based on your credit report, a document filled with your loan and credit history. You have the right to one free credit report from each of the three major credit bureaus every year through www.annualcreditreport.com.

Unfortunately, many young adults learn too late which behaviors lead to a rotten score - mainly paying bills late, opening a lot of credit cards and carrying too much debt.

College financial aid counselor Carly Eichhorst attributes some of this behavior to youth and inexperience. "They just think 'Hey, I missed (the due date), big deal.'" But some of it also comes from how complex using credit can be - so much so that everyone could use a minor in the subject.

That's why Eichhorst developed Dollar/Sense, a two-week program of informal talks about credit and other financial topics. Visit www.whatsmyscore.org - a Web site developed by the St. Paul Foundation that's now run by Visa - for similar information online.

At the program recently, senior Justin Ingebretson said he was surprised that prospective employers sometimes look at credit scores to help decide whether you're a risky hire or a sure thing.

Sophomore Nou Chang said she didn't realize "how everything in your life will depend on credit" - buying a car or a house, even renting an apartment or getting a job.

Take that car. According to Fair Isaac, someone with a score of 720 or above would receive about a 7 percent interest rate to buy a $15,000 Toyota Scion, compared with about 15 percent for someone with a score between 500 and 589. That amounts to nearly $60 more per month, or more than $2,000 by the time the car is paid off in three years.

So how is the score calculated?

Your payment history makes up 35 percent of your score. The other main consideration is the amount owed, which accounts for 30 percent. The number of credit inquiries (although not ones you initiate) and number of new accounts make up 10 percent of your score. So do types of credit and loans you have - a diverse mix of credit cards and loans for things like cars and student loans is best. The remaining 15 percent comes from the length of your credit history.

Clearly, young people are challenged when it comes to that final category, but Fair Isaac stresses that young people can have a good score if they rate high in other areas.

By all means, don't obsess about your exact score, especially if it's above 700. You don't need the equivalent of an A+ for your finances to be at the top of the class.

Kara McGuire writes for the Minneapolis-St. Paul Star Tribune

INFO BOXES:

Seven common mistakes that can lower your credit score

1. Paying bills late.

2. Not paying the minimum amount required.

3. Keeping debt levels too high.

4. Owning too many credit cards.

5. Not alerting current or potential creditors if you've moved or changed names.

6. Not periodically checking your credit report.

7. Not using your full legal name in financial documents.

Six ways to improve your credit score

1. Pay your bills on time.

2. Keep your balance low in relation to your available credit.

3. Make more than the minimum payment.

4. Don't open a lot of new accounts over a short period of time, especially if you have a short credit history.

5. Pay off credit card debt rather than moving it around to other cards.

6. Review your credit report regularly and correct any significant errors.

Top five credit myths

Myth 1: My score will drop if I check my credit.

Myth 2: Once I pay off a negative record, it will be removed from my credit report.

Myth 3: My poor score will be with me forever.

Myth 4: Paying off my debt will add 50 points to my credit score.

Myth 5: Closing old accounts will improve my credit score.

Source: www.whatsmyscore.org