More For Your Money - University of Illinois Extension

How Are Credit Scores Created?

The credit score is created by five factors: 

Payment history: 35%, Amounts owed: 30%, Length of credit history: 15%, New credit: 10%, Types of credit used: 10%

Payment History 35%
This is how you have paid your bills in the past.
Outstanding Debt 30%
This looks at how much you owe on your accounts.  It looks at the number of accounts with balances.  It reflects how much of your available credit you are using.
Length of your Credit History 15%
The longer you have credit will increase your score. However, you can get a high score with a short credit history if the rest of your credit report shows responsible credit management.
Recent Inquiries on Your Report 10%
How many credit applications are you filling out? The factor considers people who are rate shopping for the best mortgage or car loan rates.  Credit shopping with too many inquiries may hurt your score, especially if you have had recent credit problems, such as late payments or bills sent to collections.
Types of Credit in Use 10%
The best scores will have a mix of both revolving credit, such as credit cards, and installment credit, such as mortgages and car loans. Consumers who have a variety of credit loans are often better credit risks.

Source: Your Credit Scores - FICO® and My FICO®