Utilization, and the under-30% rule of thumb
Okay. Last lesson we went through the five things that move your score. If you were paying attention you probably noticed I spent, like, ten seconds on payment history and then a whole chunk of time on this next thing. That's on purpose. Utilization is the one people actually have day-to-day control over, so it's the one worth slowing down on.
Here's the definition, plain: utilization is how much of your available credit you're using, shown as a percentage. You have a card with a $2,000 limit. You're carrying a $600 balance. That's 30% utilization on that card. Simple math, mostly.
The "mostly" is doing some work in that sentence and I'll get to why in a second.
The rule of thumb
Under 30% is the number everybody throws around, and it's a fine rule of thumb. Under 10% is even better if you can swing it. Over that 30% line, the score models start treating you like you're leaning on credit harder than you should be — doesn't matter if you pay it off in full every month, doesn't matter if you've never missed a payment in your life. The models are looking at a snapshot, usually whatever your balance is when the statement closes, and they don't know your intentions. They just see the number.
I feel like this is the part that trips people up the most, actually — the idea that paying in full doesn't protect you here. You can be completely responsible and still get dinged on utilization if your statement happens to close on a $1,800 balance against a $2,000 limit. The card doesn't know you were going to pay it off Friday.
Where it gets messy
So here's the "mostly." Utilization gets looked at two ways — per card, and across all your cards combined, total balances over total limits. And honestly? The exact way each of those gets weighted against each other in the scoring formula, I have to look up every single time. I'm not going to pretend I've got that memorized down to the decimal, because I don't, and I don't think most people need to either.
What I do think you need to know is the practical version: keep every individual card under 30% if you can, and keep your overall picture under 30% too. If one card's high and the rest are empty, that one card can still drag things down even if your total looks fine on paper.
What you can actually do this week
A few things, in order of "easiest to just go do right now":
- Pull up each card and find the limit. Not the balance — the limit. A lot of people know what they owe but genuinely don't know their limit, which is wild when you think about it, because that's half the math.
- Do the division. Balance divided by limit, times 100. Write it down next to each card from your list, same list we started building a couple lessons ago.
- If a card's over 30%, don't panic, just notice it. That's this lesson. Fixing it is a different lesson.
- If you've got room on another card and a big balance stacking up on one, moving some of it over can help the number — but only if you're not just making room to spend more. That's the trap. Utilization math doesn't care why the balance is low, but your actual life does.
One caution here, real one: don't go closing a paid-off card because you think it'll "clean things up." Closing a card lowers your total available credit, which can actually push your utilization percentage up even though you owe the same amount. Counterintuitive, I know. Leave old paid-off cards open unless there's an annual fee that's genuinely not worth it.
The math-optimal answer isn't always the right one
I'll say the same thing here I said back when we talked about paying down balances generally — there's a "correct" order to attack this stuff if you're going purely by the numbers. Tackle whatever's highest interest, or whatever's closest to that 30% line, first.
I tried that. The avalanche method, highest interest first. It's the mathematically smart move and I did it for about two months and then quit, because nothing felt like it was moving. I'd throw money at the worst card and the balance barely budged and I lost steam. Switched to knocking out my smallest balance first instead — worse math, better human — and that's what actually got me through it.
So if you're looking at your utilization numbers and one card's technically the "right" one to pay down first by the math, and it's demoralizing... it's fine to pick a different one. I'd rather you keep going on the wrong card than quit on the right one.
Before next time
Get the balance-over-limit number written down for every card on your list. Don't fix anything yet, we're just building the picture. No worries at all if a few of them are higher than you expected — that's kind of the point of doing the math instead of guessing.