Independent agencies use rather complex and secret formulas to calculate your credit score. However, your available line of credit is factored into the calculations. Generally, the higher your line of credit, the higher your score. Formulas The precise formulas used by the major credit rating agencies are kept secret, as the exact formulas are trade secrets. However, we do know that a few critical factors have the greatest impact on your credit score. These include your payment history, the length of your credit history, types of credit,...