Credit Utilisation Ratio

The credit utilisation ratio is the percentage of a borrower's total available credit that is currently being actively used, most commonly measured across revolving accounts such as credit cards. It is calculated by dividing total outstanding balances by total credit limits across all open accounts combined, or alternatively calculated separately on a per-card basis for a more granular view of utilisation.

After payment history, credit utilisation is typically the second most heavily weighted single factor within widely used credit scoring models, which is precisely why financial advisers so routinely recommend keeping outstanding balances well below available limits rather than habitually running accounts close to their stated maximum.

If you have a single credit card with a $10,000 limit and carry a $3,000 balance on it, your utilisation ratio works out to 30 percent. Carrying $9,000 on that very same card instead pushes utilisation up to 90 percent — a genuine red flag to most scoring models, even if every single payment has always been made on time without exception, because it suggests the borrower may be relying rather heavily on available credit just to get by.

The underlying formula is straightforward:

• $\text{Total balances}$ is the sum of all outstanding balances across revolving accounts being measured.
• $\text{Total credit limits}$ is the sum of the credit limits attached to those same specific accounts.

High utilisation suggests a borrower may be financially stretched or increasingly reliant on credit simply to cover ordinary day-to-day expenses, which correlates statistically with a meaningfully higher risk of future default, entirely independent of that same borrower's documented payment history up to that point in time.

Many credit experts suggest keeping overall utilisation below roughly 30 percent, with utilisation under 10 percent generally associated with the very strongest credit scores achievable, though the exact impact of any given utilisation level genuinely varies by the specific scoring model used and an individual's own broader overall credit profile.

Utilisation is generally measured and reported to the bureaus based specifically on the balance showing on a card's statement closing date, not necessarily the balance sitting on the account at the exact moment a score happens to be checked, which means paying down a balance before the statement closes — rather than only before the payment due date — can meaningfully lower reported utilisation and genuinely help a score sooner than many cardholders realize.

Some scoring models look not only at a borrower's overall utilisation across every account combined but also at utilisation on each individual card separately, meaning a single maxed-out card can still noticeably hurt a score even if the borrower's combined utilisation across all their other, largely unused cards remains comfortably low overall.

Opening a brand-new credit card specifically to lower overall utilisation can initially have a mixed effect on a score, since the new account briefly lowers the average age of credit history even as it increases total available limit; most scoring models eventually reward the lower resulting utilisation once the new account has been open for a reasonable period, but the short-term effect of the new account itself is not always immediately positive.

A straightforward way to lower utilisation without paying down any existing balance is to request a credit limit increase on an existing card, since the formula's denominator grows while the numerator stays the same, though this approach works only if the issuer grants the increase and the cardholder does not simply spend up to the new, higher limit over time.

Advisers generally caution that a limit increase only genuinely helps the ratio if spending habits stay the same afterward, since the benefit disappears entirely if the cardholder treats the newly available credit as an invitation to spend more each month.