Credit Utilization
Definition
Credit utilization is how much of your available revolving credit you are using at a given moment, shown as a percentage. It is measured per card and across all cards together.
With $10,000 of total card limits and a $3,000 balance, utilization is 30%.
It is one of the more responsive inputs to a credit score, because it reflects the balance reported at a point in time rather than a long history. Paying a balance down before the statement date changes the figure that gets reported.
Utilization applies to revolving credit such as cards and lines of credit. Installment loans, where the balance only falls, are not counted the same way.