Your FICO credit score is built from exactly five things, and two of them account for about two-thirds of the whole number. If you only remember one sentence from this article, make it this: pay on time, and keep your balances low. That's payment history (35%) and amounts owed (30%) working together. Everything else is fine-tuning.

A FICO score runs from 300 to 850, and the national average sat at 714 in 2026. Lenders generally treat 670 and up as "good," while the best interest rates usually go to people above 740. But the number itself is less useful than knowing what moves it. Here's the full breakdown, ordered by how much weight each factor carries.

Payment History (35%) — The Single Biggest Factor

Payment history is whether you pay your bills on time, and it's more than a third of your score. FICO looks at how many payments were late, how late they were (30, 60, 90+ days), how recently the most recent late payment happened, and how much was owed. A single payment that's 30 days late can knock a good score down by 50 to 100 points—and it can sit on your credit report for up to seven years.

The practical move here is boring but powerful: never miss a due date. Set every bill you can to autopay for at least the minimum, so a busy month never turns into a derogatory mark. One missed payment undoes months of careful credit-building, which is why this factor deserves your attention before any other.

Amounts Owed (30%) — Your Credit Utilization

The second-biggest factor isn't how much debt you have in dollars—it's what percentage of your available credit you're using. This is your credit utilization ratio, and the rule of thumb is to keep it under 30%, with under 10% being ideal for top scores. If you have a $10,000 total credit limit and you're carrying a $4,000 balance, your utilization is 40%, and that's already dragging your score down.

What surprises people is how fast this factor reacts. Unlike payment history, which takes years to repair, utilization resets every billing cycle. Pay your balances down before the statement closes and your score can jump within a month. We break the mechanics down in detail in our guide to how credit utilization impacts your score—it's the fastest lever most people can pull.

Length of Credit History (15%)

This factor measures how long you've had credit: the age of your oldest account, the age of your newest, and the average age across all of them. Older is better, because a long track record gives lenders more data to trust. This is the main reason financial advisors tell you not to close your oldest credit card—doing so can shorten your average account age and ding your score.

It's also why getting added as an authorized user on someone else's long-standing account can help a newcomer: you can inherit the age and payment history of that account. We cover when that actually works in our piece on whether adding an authorized user helps build credit.

New Credit (10%) and Credit Mix (10%)

The last two factors are smaller, but worth understanding.

New credit (10%) tracks how many new accounts you've opened recently and how many "hard inquiries" you've triggered by applying for credit. Each hard inquiry can shave a few points off temporarily, and a flurry of applications in a short window signals risk to lenders. The fix is simple: space out your credit applications and don't apply for cards you don't need.

Credit mix (10%) rewards having a variety of credit types—say, a credit card and an installment loan like a car loan or mortgage. You don't need to take on debt just to diversify; this is the least important factor, and chasing it by borrowing money you don't need is a bad trade. It improves naturally over a financial lifetime.

Putting It Together

Notice what's missing from this list: your income, your savings, your job, and your age aren't part of your FICO score at all. The score is purely a measure of how you've handled borrowed money. That's freeing, because it means the controls are entirely in your hands.

If you want to improve your score, work the factors in order of weight. Lock in on-time payments first (35%). Then drive your utilization below 30% (30%). Keep old accounts open (15%), apply for new credit sparingly (10%), and let your credit mix develop on its own (10%). Before you make any moves, it's worth pulling your reports and confirming the data is accurate—mistakes are common, and our guide on how to read your credit report and what to dispute shows you what to look for.