Credit utilization: how the 30% rule works
Key takeaways
04 · ideas- Utilization is calculated on the statement closing date, not the due date
- Lower utilization generally correlates with higher scores across all ranges
- Per-card utilization matters separately from overall utilization
- High utilization is fully recoverable — it has no memory in FICO models
Basic level
The essentials · 1 min
Credit utilization is the percentage of available revolving credit currently in use. If you have $10,000 in credit card limits and $2,500 in balances, your utilization is 25%.
The common advice to keep utilization below 30% reflects a general guideline. The actual scoring relationship is more continuous: lower utilization generally corresponds to higher scores, with the optimal range often cited as 1-10%.
Key fact: Utilization has no memory in FICO models. Unlike a missed payment (which stays on your report for 7 years), utilization is recalculated each scoring cycle based on current reported balances. Paying down a balance typically improves the score as soon as the new balance is reported.
Intermediate level
How it applies · 1 min
When balances are reported
Credit card issuers typically report your balance on your statement closing date — not the payment due date. To lower reported utilization: pay the balance before the statement closes rather than before the due date.
Per-card vs. overall utilization
Both aggregate utilization (all balances divided by all limits) and per-card utilization affect the score. A single maxed-out card can hurt your score even if your overall utilization is low.
Example:- Card A: $500 balance / $5,000 limit = 10%
- Card B: $4,500 balance / $5,000 limit = 90%
- Overall: $5,000 / $10,000 = 50%
Both the 50% overall and the 90% on Card B would typically have negative impacts.
Advanced level
The math, step by step · 1 min
Scoring curve characteristics
FICO does not publish exact utilization scoring curves. Empirical analysis suggests a nonlinear relationship where the impact of utilization increases at higher percentages. High-score consumers tend to experience larger absolute point drops from utilization increases than lower-score consumers, because they have more room to fall and fewer other negative factors present.
Installment loans (mortgages, auto loans) are not included in utilization calculations — only revolving accounts.