Your credit score is calculated from five groups of data that are reported to the credit bureau. The percentages in the chart reflect how crucial each of the sections is in determining how your credit score is calculated.
35%: Your Payment History. Have you made all of your payments on time? Repayment of debt is the most important part of your credit score. This includes both revolving loans (credit cards) and installment loans, like mortgages and student loans.
30%: Amount Currently Owed. 30% of your credit score takes into account the amount of credit that you are already borrowing. For example, borrowers who continuously max out credit cards are not considered people who can handle debt responsibly.
As you can tell, these two factors make up 65% of your credit score. So if you are good about making payments on time, and you don't have large amounts owed, you probably have a decent credit score.
15%: Length of Credit History. It's impossible for a person who is new to credit to have a good credit score. FICO takes into account the amount of time you've held credit, and if you have good long-term financial behavior, your score will reflect that.
10%: The Types of Credit Used. Borrowers should have a "credit mix" - which means that they borrow funds for a number of reasons. Someone who has a mortgage, student loan and credit card is more well-rounded than someone who has three different lines of student loan debt. A credit mix shows that you're able to responsibly handle credit of all types.
10%: New Credit. Your credit score takes into account how often you're requesting for credit. Someone who takes out five credit cards gives off the image that they are in financial duress, so it's best to take out loans only when it makes financial sense.