How the Credit Utilization Calculator works
Credit utilization is the percentage of your available revolving credit that you're currently using. It's calculated with a simple ratio: divide the balances you owe by the credit limits you've been given, then multiply by 100. Scoring models weigh this ratio heavily because it signals how close you are to maxing out your available credit, independent of how much you actually spend each month.
The formula
Utilization % = (Total balances ÷ Total credit limits) × 100
This calculator applies that formula twice: once across both cards combined (your overall utilization), and once per card, so you can see whether one account is carrying a disproportionate share of the balance even if the combined number looks fine.
Worked example
Say Card 1 has a $1,200 balance on a $5,000 limit, and Card 2 has an $800 balance on a $3,000 limit. Combined balances are $2,000 against combined limits of $8,000, so overall utilization is $2,000 / $8,000 × 100 = 25%. Individually, Card 1 sits at 1,200/5,000 = 24% and Card 2 at 800/3,000 ≈ 26.7% — close to each other in this example, but that won't always be the case.
Paying down to a target ratio
To find how much you'd need to pay off to reach a target ratio, rearrange the formula: Amount to pay = Total balance − (Target % × Total limit). Using the example above with a 10% target: pay down to $2,000 − (0.10 × $8,000) = $2,000 − $800 = $1,200. If the result comes out negative, your balances are already under that target and no payment is needed to reach it.
Why per-card utilization matters too
- One maxed card can outweigh a good average: a card sitting at 90% utilization can drag down your score even if your overall ratio across all cards looks moderate.
- Limits change the math, not just balances: a $500 balance is 50% on a $1,000 limit but only 5% on a $10,000 limit — the balance alone doesn't tell the story.
- Common guideline: many credit education sources suggest keeping overall utilization under 30%, with under 10% often cited as ideal for those chasing top-tier scores. This calculator does not access your credit report or score — it only performs the balance-to-limit arithmetic on the numbers you enter.