Credit Utilization
Credit utilization is the percentage of your available credit that you're currently using. It's calculated by dividing your total credit card balances by your total credit limits. Credit utilization is the second-largest factor in FICO scores (about 30% of the calculation), and lower utilization generally produces higher scores.
Credit utilization measures how much of your available revolving credit (credit cards, primarily) you’re using at any given time. If you have $10,000 in total credit card limits and $3,000 in current balances, your utilization is 30%.
The score impact
FICO scoring puts utilization second only to payment history. The conventional advice is to keep utilization below 30%, but the data is more nuanced:
- Below 10%: optimal for score
- 10-30%: still good, minor score impact
- 30-50%: meaningful negative score impact
- 50-90%: significant score impact
- Above 90%: large score impact
Going from 50% utilization to 10% can boost your score 30-50 points within a single billing cycle.
Per-card vs aggregate
FICO looks at both your per-card utilization and your aggregate utilization. A single maxed-out card can drag your score even if your overall utilization is low. If you’re optimizing for score, spread balances across cards rather than concentrating on one.
Why it updates fast
Unlike payment history (which builds over years), utilization updates monthly when card issuers report your statement balance to the bureaus. A balance you carry today and pay down before the next statement date can drop your reported utilization to near-zero, with score impact visible within 30-45 days.
This makes utilization the fastest score-improvement lever for most borrowers. If you need a higher score for an upcoming application, paying down card balances is the fastest move.