Credit Utilisation, and Why the 30% Rule Is Folklore

Credit utilisation is the share of your available revolving credit that you are currently using. It is one of the heaviest factors in most credit scoring models, and it is also the subject of more confident misinformation than any other part of the system.

The calculation

Utilisation is your balance divided by your credit limit.

• $1,500 balance on a $5,000 limit is 30% utilisation
• $500 on a $5,000 limit is 10%

It is measured two ways at once: per card, and overall across every revolving account you hold. A single card run close to its limit can matter even when your total across all cards is modest.

Note what is excluded. Utilisation is a revolving-credit concept, so it applies to credit cards and lines of credit. Instalment debt like a mortgage, car loan or personal loan is not part of it, because those do not have a limit you can run back up.

The 30% figure is not a threshold

Here is the part worth being blunt about. The widely repeated advice to "keep utilisation under 30%" describes a rule that does not exist in any published scoring model.

The CFPB's guidance is to keep your balance low relative to your limit. It does not name a cutoff, because there is no cliff to name. Utilisation works as a gradient: lower is better, continuously. Going from 31% to 29% does not trip a switch. Going from 80% to 40% helps considerably, and going from 40% to 10% helps again.

Treat 30% as a rough waypoint that is better than 60% and worse than 10%, not a line you are safe behind.

It is a snapshot, not an average

This is the mechanically useful part, and most people do not know it.

Your issuer reports your balance to the credit bureaus periodically, typically around the statement closing date. That single figure becomes your reported utilisation until the next report. Scoring models see the snapshot, not your daily average and not your payment history within the cycle.

The consequence: someone who pays their statement in full every month can still show high utilisation. If you charge $2,000 on a $3,000 limit and pay it off in full after the statement closes, the bureaus were shown 67%. You pay no interest, you owe nothing, and your reported utilisation is poor anyway.

The fix is timing. Paying down the balance before the statement closing date, rather than before the due date, lowers the figure that gets reported. Those are two different dates, and only one of them affects utilisation.

What raises utilisation without you spending anything

• Closing a card. The balance stays and the limit vanishes, so the ratio rises. This is the main reason closing an unused card can hurt
• A limit reduction. Issuers sometimes cut limits on inactive accounts, which raises utilisation on any balance you carry
• A large purchase timed badly. Even a purchase you intend to pay off immediately can land inside the reporting snapshot

Conversely, a limit increase lowers utilisation instantly without you paying anything, though asking for one may involve a credit check.

What to actually do

• Pay before the statement closes, not just before the due date, if you want the reported figure low
• Keep old cards open, even unused ones, since the unused limit is helping you
• Spread balances rather than maxing one card, since per-card utilisation is visible
• Do not chase a specific percentage. Lower is better, and there is no number at which you have won

One caveat on all of this: utilisation is a large factor but not the largest. Payment history carries more weight in most models, and no amount of utilisation management offsets a missed payment. See what actually affects your credit score for how the factors compare.

A worked example across several cards

Abstract percentages are hard to reason about, so here is a concrete portfolio.

Overall utilisation here is 27%, which sits comfortably under the widely repeated 30% figure. Someone using that number as a pass mark would conclude there is nothing to fix.

But Card A is at 90%, and per-card utilisation is visible to scoring models. This portfolio looks considerably worse than its headline number suggests, and the fix is obvious once the figures are laid out: money should go to Card A first, even though every card is affordable and none is in trouble.

Pay $1,500 against Card A and it drops to 40%, while overall utilisation falls to about 15%. The same $1,500 spread evenly would produce the same overall figure while leaving Card A at 73%.

The reporting calendar, laid out

The single most useful thing to understand is which day your balance is captured. Here is a typical month for a card with a statement closing on the 15th and payment due on the 10th of the following month.

The person in this example is behaving impeccably. They pay in full, they owe nothing, they pay no interest, and their reported utilisation is 60% for the entire following month.

Moving the payment to the 13th, two days before the statement closes, changes the reported figure to near zero without changing anything about their spending or their interest cost. That is the whole trick, and it costs nothing.

To use it you need to know your statement closing date, which is on your statement and in your online account. It is rarely the same as your due date and is often not the 1st.

Should you aim for zero?

Not quite, and this is a genuine subtlety rather than a myth.

Utilisation is a gradient with lower being better, but a report showing zero balances on every revolving account gives models very little recent activity to assess. Many scoring models treat a small reported balance slightly more favourably than none at all.

The practical version, if you are optimising for a specific application:

• Let one card report a small balance, a few percent of its limit
• Pay the others down before their statement dates
• Pay everything in full by the due dates, so you still owe no interest

This is fine-tuning, not a foundation. The difference between 1% and 0% is trivial compared with the difference between 60% and 10%, and neither compares with the effect of a missed payment.

Things that change your ratio without any spending

• Closing a card. Your balances are unchanged, your total limit falls, and utilisation rises across the board. On the portfolio above, closing Card B alone would take overall utilisation from 27% to about 50%.
• An issuer cutting your limit, which happens on inactive accounts and during economic tightening. You may not be told prominently.
• A limit increase, which improves the ratio instantly. Some issuers grant these with a soft pull; others do a hard inquiry, so ask which before requesting.
• Being added as an authorised user on someone else's card, which can add their limit and their balance to your report. Helpful if their utilisation is low, harmful if it is not.
• A large purchase landing just before the snapshot, even one you intend to clear immediately.

What is not counted

Utilisation is a revolving-credit measure. These do not have a limit you can run back up, so they do not form part of the ratio:

• Mortgages
• Car loans
• Student loans
• Personal instalment loans

A $300,000 mortgage does not give you 100% utilisation. It is assessed under amounts owed and payment history instead. Someone with a large mortgage and one lightly used credit card can have excellent utilisation. See secured vs unsecured loans for how these different debt types are structured.

A checklist you can run in ten minutes

1. Find the statement closing date for every card you hold. Write them down.
2. Note each card's balance and limit, and work out per-card and overall utilisation.
3. Identify the card with the highest per-card figure. That is where money goes first.
4. Move any recurring payment or transfer to land a few days before the closing date rather than before the due date.
5. Check whether any issuer has quietly reduced a limit.
6. Leave fee-free cards you no longer use open, and put a small recurring charge on one so it is not closed for inactivity.

Done once, this takes a single sitting. Repeated when something changes, it keeps the fastest-moving factor in your credit profile pointed in the right direction.

Sources

• CFPB: What is a credit score?
• CFPB: Credit reports and scores
• CFPB: Credit cards

Current as of August 2026. Scoring models are proprietary and weightings are not published; the mechanics described here are drawn from CFPB consumer guidance.