How is credit utilization calculated?

At a glance#

What utilization measures#

Credit utilization puts two numbers side by side, and both appear in the credit report: the reported balance of an account and that account’s credit limit. The result is a ratio, and from a lender’s point of view the ratio answers one question only: how heavily somebody is drawing on the lines granted right now.

Utilization belongs to the factor group of amounts owed, and the best known scoring vendor gives that group a weight of 30 % for the general population. Only payment history weighs more, and payment history cannot be improved quickly. Utilization, by contrast, changes with every reporting cycle and hinges on a date that hardly anybody knows, which makes it the most practical lever in the whole report.

Newcomers tend to equate utilization with debt, which it is not; it is a snapshot of one day’s balance against the line granted. For somebody who has just moved to the US from Germany, Austria, Switzerland or anywhere else, the ratio has one more twist: with a short file and one or two cards, every month’s reported balance weighs more than it would in a long history.

Which balance gets reported#

The statement date decides, not the payment date#

A card account runs through two dates each month. On the statement date the issuer closes the cycle, produces the statement and sends that day’s balance to the credit bureaus. By the due date, a few weeks later, the payment has to arrive for purchases to stay free of interest.

The balance reported is therefore a balance from before the payment. Paying everything on the due date prevents interest, but the figure already reported stays in the file: utilization follows the first date, interest the second. Both dates and their separate effects are laid out in What is the difference between the statement date and the due date?.

The two dates produce the contradiction newcomers run into most often. Somebody has paid on time and in full for years, runs a lot of spending across the card, and still shows a high ratio month after month. Nothing is wrong and nothing is missing from the payment history; the reporting date simply falls before the payment.

Per card and across all cards#

Utilization is calculated twice. Once per account, by dividing that account’s reported balance by its own limit, and once across all accounts, by dividing the sum of all balances by the sum of all limits.

Both figures enter the assessment, and the two can be far apart. A single card close to its limit stands out even when the total looks unremarkable, while one empty card does little when the other lines are heavily used. So the card with the highest individual ratio comes down first, and the total gets optimised afterwards.

The limit is the other half of the fraction#

Utilization can be lowered from two sides, a smaller balance or a larger limit. Both routes lead to the same number on paper, with very different side effects.

A higher credit limit lowers the ratio without any change in behaviour. Whether a limit increase triggers a hard inquiry is the issuer’s decision, and the answer is usually stated in the request form before anything is submitted. What such an inquiry does to the file is covered in Hard pull or soft pull.

Closing an account works in the opposite direction. The limit disappears from the total, the spending stays, and overall utilization rises. With only a few accounts, a single closure can push the ratio up sharply without anybody spending more. Where an annual fee is the reason for closing, Cancel the card or downgrade it? sets out the alternative that keeps the limit in place.

Three ways to lower the reported ratio#

Three levers exist, and they differ a great deal in effort and side effects.

Pay before the statement date. This is the most effective route and the simplest. A payment a few days before the cycle closes lowers the balance that gets reported, without changing the regular payment rhythm.

Spread the spending. Two cards with moderate ratios look different from one maxed out card next to an empty one, even when the total is identical. Spreading pays off mainly when one account keeps hitting its limit, for example because a large recurring charge runs through it.

Raise the limit. The lever with the largest effect and the most unpleasant side effect, because some issuers review creditworthiness again. Before asking, find out whether a hard inquiry will be made.

Overpaying is not one of the levers. A credit balance on the card is normally reported as zero, never as a negative amount, so overpaying achieves nothing beyond a full payment.

What utilization is not#

Utilization is not debt. The ratio describes a balance on one day, not money owed over months. Somebody who pays in full every cycle has no debt at all, and may still show a high reported ratio.

Utilization has no memory. Unlike a missed payment, which stays visible for years, the ratio is reported fresh each month and replaces the previous one.

Utilization is not a judgement on spending. How much somebody spends is irrelevant to the ratio, as long as the relation to the limit is fine. Heavy spending on a large line stands out less than moderate spending on a small one.

Worked example: three cards, one month#

The figures are assumptions, and the currency does not matter; the ratio is the point. Take a newcomer with three cards. Card A has a limit of 2,000, card B a limit of 6,000 and card C a limit of 12,000, so the lines add up to 20,000. All regular spending of 1,800 a month runs through card A, and cards B and C sit unused.

Running everything through card A is the trap. The overall ratio of 9 % looks harmless, yet one card reports 90 %, and that single card is what stands out. Nothing about the person’s finances is wrong; the problem is a small limit carrying all the spending up to the statement date.

One extra payment before the statement date fixes the problem. Spreading the spending fixes the single card ratio as well, but leaves the overall figure unchanged.

In all three columns no interest is charged and the payment history is spotless. Paying early manipulates nothing; the cardholder only chooses which balance gets reported.

What to make of the thirty percent rule#

Advice columns repeat a rule that utilization must stay below thirty percent. No official basis for that line exists, and no scoring vendor describes it as a threshold.

What the vendors do describe is a sliding relationship: lower is better, all the way down. A ratio of ten percent scores better than one of twenty nine, although both sit below the supposed limit. Treating the rule as a threshold means stopping exactly where there is still room to improve. As a rough warning mark the rule of thumb still works, since a ratio that stays above it month after month means the lines are heavily used. As a target it fails.

Where to read your own ratio#

Your own utilization can be checked in three places, and they do not show the same thing.

On the statement. The statement shows the balance on the statement date, which is the very number that gets reported, and the limit usually sits right next to it. Dividing one by the other gives the ratio the issuer passed on, without any app.

In the credit report. The report shows the last reported balance for each account, and it exposes wrong limits. A limit reported too low drives the ratio up, and that error can be disputed. How the report itself is built is explained in How do I build a US credit report from scratch?.

In the issuer’s app. The app shows today’s balance. For the report that figure is irrelevant, but it is the right number to check a few days before the statement date.

Keeping the three views apart explains the most frequent confusion: the app shows a high number, the report a low one, and both are correct because they describe different days.

When it is not worth optimising#

Three situations make fine tuning the ratio pointless:

• No application in sight. The ratio changes monthly and has no memory. Without an application in the foreseeable future, keeping it permanently low gains nothing.
• An open missed payment. A missed payment outweighs any ratio. While a delinquency is open, the attention belongs there.
• Interest on the balance. Carrying a balance from one cycle to the next costs interest, and that cost exceeds any benefit from a lower reported ratio. The numbers are in When does interest arise on a credit card?.

On an empty file the whole question falls away, because without reported accounts there is no utilization at all. How the scoring models weigh the ratio once it exists is compared in FICO or VantageScore: which number decides.

The most common mistakes#

• Taking the due date for the reporting date. The statement date decides what gets reported, and the due date only decides about interest.

• Watching only the overall ratio. Every card is rated on its own too, and the highest single ratio stands out first.

• Closing cards to tidy up. Each closure removes limit from the total and raises the ratio, while an unused card without a fee costs nothing to keep open.

• Not using the card at all. A small, regularly reported balance usually scores better than an account without any activity.

• Treating the thirty percent rule as a target. Lower is better on a sliding scale, and no threshold exists.

• Asking for a higher limit without checking the inquiry. If the issuer makes a hard inquiry, a small improvement in the ratio is paid for with a new entry in the file.

Several cards with the same issuer#

Several cards with the same issuer are still several accounts in the file, each with its own limit. Moving spending between them changes the individual ratios and leaves the total where it was.

Some issuers allow limit to be moved from one card to another without a new credit check, which defuses a single high ratio without shifting spending or risking an inquiry. Whether an issuer offers that is written in its terms, not in its advertising.

Related topics#

• What is the difference between the statement date and the due date?
• FICO or VantageScore: which number decides
• When does interest arise on a credit card?
• Business credit and personal liability
• Application rules: why the order matters