How does Credit Scoring Works? How is a Score Calculated?

Ever wonder why you can go online and be approved for credit within 60 seconds? Or get pre-qualified for a car without anyone even asking you how much money you make? Or why you get one interest rate on loans, while your neighbor gets another?

The answer is credit scoring.

Your credit score is a number generated by a mathematical algorithm -- a formula -- based on information in your credit report, compared to information on tens of millions of other people. The resulting number is a highly accurate prediction of how likely you are to pay your bills.

If it sounds arcane and unimportant, you couldn't be more wrong. Credit scores are used extensively, and if you've gotten a mortgage, a car loan, a credit card or auto insurance, the rate you received was directly related to your credit score. The higher the number, the better you look to lenders. People with the highest scores get the lowest interest rates.

Scoring categories
Lenders can use one of many different credit-scoring models to determine if you are creditworthy. Different models can produce different scores. However, lenders use some scoring models more than others. The FICO score is one such popular scoring method.

Its scale runs from 300 to 850. The vast majority of people will have scores between 600 and 800. A score of 720 or higher will get you the most favorable interest rates on a mortgage, according to data from Fair Isaac Corp., a California-based company that developed the first credit score as well as the FICO score.

Fair Isaac reports that the American public's credit scores break out along these lines:

Currently, each of the three major credit bureaus uses their own version of the FICO scoring method -- Equifax has the BEACON score, Experian has the Experian/Fair Isaac Risk Model and TransUnion has the EMPIRICA score. The three versions can come up with varying scores because they use different algorithms. (Variance can also occur because of differences in data contained in different credit reports.)

That could change, depending on whether a new credit-scoring model catches on. It's called the VantageScore. Equifax, Experian and TransUnion collaborated on its development and will all use the same algorithm to compute the score. Consumers can order their VantageScores online at Experian's Web site for $6. Its scoring range runs from 501 to 990 with a corresponding letter grade from A to F. So, a score of 501 to 600 would receive an F, while a score of 901 to 990 would receive an A. Just like in school, A is the best grade you can get.

What's the big deal?
No matter which scoring model lenders use, it pays to have a great credit score. Your credit score affects whether you get credit or not, and how high your interest rate will be. A better score can lower your interest rate.

The difference in the interest rates offered to a person with a score of 520 and a person with a 720 score is 4.36 percentage points, according to Fair Isaac's Web site. On a $100,000, 30-year mortgage, that difference would cost more than $110,325 extra in interest charges, according to Bankrate.com's mortgage calculator. The difference in the monthly payment alone would be about $307.

Powerful little number
If you rented an apartment, got braces, bought cell phone service, applied for a job that involved handling a lot of money, or needed to get utilities connected, there's a good chance your score was pulled.

If you have an existing credit card, the issuer is likely to look at your credit score to decide whether to increase your credit line -- or charge you a higher interest rate, according to a credit scoring study by the Consumer Federation of America and the National Credit Reporting Association.

Buying a car? Most car dealers want to know your credit score when you walk in the door, says Bob Kurilko, vice president of product development and marketing for Edmunds.com, an online consumer resource for automotive issues. "They want to know how they can put a loan together for you."

The score has made it easier for many people to get credit, Kurilko says.

Before, it was up to individual lending institutions to come up with their own criteria, he says. "They would hedge their risk and tend to go conservatively. It's opened up lending to a lot more people."

Consumers' rights
Until recently, many Americans didn't even know this number existed because it was a closely guarded secret in the lending industry. In fact, lenders were prohibited from telling borrowers their credit score. The line of reasoning: The number was the result of analyzing complex financial data that the layperson would have difficulty understanding. Plus, if people knew their score (according to the industry mindset at the time), they might be able to change their behavior to manipulate the score and throw off the whole model, rendering it useless.

All that changed a few years ago, when consumers began finding out about the score and demanding to see it. In an unprecedented move in 2000, online lender E-Loan offered to give consumers their scores for free, with information explaining how the score is calculated and how they might improve it. Fair Isaac responded by cutting E-Loan off from its source of credit reports, effectively crippling its ability to lend money. E-Loan stopped giving away credit scores.

Public outcry on the possibility of people being denied credit based on bad information in credit reports led to several pieces of legislation -- and a much more open attitude about credit scores.

Fast forward to current day: Not only can consumers buy their score online from any number of sources, but everyone is entitled to a free copy of their credit report every 12 months from each of the three major credit bureaus -- Equifax, Experian and TransUnion. The program rolled out across the nation one geographical region at a time with all consumers eligible on Sept. 1, 2005.