What makes up your credit score

Your FICO score — the number banks use for almost every lending decision — is calculated from five factors. They aren't weighted equally, and two of them matter way more than the others. Knowing which is which is the difference between playing defense and optimizing.

The five factors

• Payment history (35%) — have you paid bills on time, and how recently did you miss one?
• Amounts owed / credit utilization (30%) — how much of your available credit are you currently using?
• Length of credit history (15%) — how old are your oldest accounts and how old is your average account?
• Credit mix (10%) — do you have a mix of credit types (cards, loans)?
• New credit (10%) — how many new accounts have you opened recently?

Payment history: the heavy, slow factor

Payment history is binary and unforgiving: a payment is either on time or it isn't, and 'on time' means within 30 days of the due date. One 30-day late on an otherwise clean file can cost 60–100 points, and it stays on your report for seven years — though its scoring weight fades substantially after about two. The flip side is that this factor asks nothing clever of you. Autopay for at least the minimum on every account converts 35% of your score into a solved problem. There is no optimization here, only reliability.

Utilization: the fast lever

Utilization is the percentage of your available revolving credit you're using, and unlike every other factor it has no memory in most scoring models — it's recalculated from whatever balances your cards report each month. Carry $3,000 against $10,000 in limits and you're at 30%; pay it to $800 before the statement closes and next month you're at 8%, and your score responds within one or two cycles. This is why someone rebuilding credit can see a 20–60 point swing in weeks: they didn't become a different borrower, they just changed the one input that reprices monthly.

What your score is worth in dollars

The score isn't a grade for its own sake — it's a price tag on every dollar you'll ever borrow. Lenders sort applicants into pricing tiers, and the gap between tiers compounds over the life of a loan. On a $350,000 30-year mortgage in early 2026, the difference between a 640 and a 780 borrower is commonly around 0.75–1% in rate — roughly $180–$230 a month, or $65,000–$80,000 over the loan. Estimated total interest paid by score band on that mortgage:

The same tiering applies to auto loans (where the subprime-to-prime gap can be 8+ percentage points of APR), credit card offers, apartment screening, and in most states even your car insurance premium. A good score is one of the few assets that pays you back on every transaction, silently, for decades.

Common myths

• Myth: checking your own credit hurts your score. False — it's a 'soft pull' and invisible to lenders.
• Myth: carrying a balance helps your score. False — you pay interest for nothing. Pay in full, on time.
• Myth: closing old cards boosts your score. False — it usually hurts utilization and length of history.
• Myth: you need debt to build credit. False — one credit card used responsibly does it.

The three factors most people ignore

The remaining 35% of your score — length of history, credit mix, and new credit — gets far less attention, partly because it moves slowly and partly because people misunderstand it. Length of history looks at the age of your oldest account, the age of your newest, and the average age across everything. This is why the standard advice is to keep your first credit card forever: a 12-year-old card anchors your average even as you add newer accounts. It's also why opening three cards in one year stings a 3-year-old file much more than a 15-year-old one — the new accounts drag the average down proportionally more.

Credit mix rewards having both revolving credit (cards) and installment credit (auto loans, student loans, mortgages) — lenders like evidence you can handle both structures. But at 10% of the score, it is never worth taking out a loan you don't need just to diversify. If a car loan or mortgage arrives naturally in your life, the mix benefit comes along for free.

New credit counts hard inquiries and recently opened accounts. A single inquiry typically costs 5 or fewer points and stops affecting your score entirely after 12 months, so one application is nearly free. The trouble is clustering: four or five applications in a few months signals possible distress, and on a thin file the combined effect can be 30–40 points. One useful exception — FICO treats multiple inquiries for the same loan type (mortgage, auto) within a 14–45 day window as a single inquiry, specifically so you can rate-shop without penalty. Shop lenders aggressively for big loans; ration card applications.

What this looks like in practice

Take a concrete case. Priya has a 668 score: two cards with $4,200 in balances against $9,000 in limits (47% utilization), a 4-year-old auto loan paid perfectly, and one hard inquiry from last spring. Her payment history is clean, so the biggest drag by far is utilization. She pays the balances down to $850 total before her statement dates — utilization drops to 9% — and does nothing else. Two months later she's at 721. No disputes, no new products, no tricks: she simply moved the one heavily weighted factor that reprices monthly. Contrast that with her brother, whose 668 comes from a 60-day late eight months ago. His utilization is already low; his only lever is time and an unbroken streak of on-time payments, and his climb back to 720 will take a year or more. Same number, completely different problem — which is why knowing the factor weights matters more than knowing the score.

1. 1
   Put every account on autopay

   At least the minimum, on every card and loan. This makes the 35% factor untouchable and protects you from the single most expensive mistake in credit — the 30-day late.

2. 2
   Get reported utilization under 10%

   Pay balances down a few days before each card's statement closing date, not just the due date. The statement balance is what gets reported to the bureaus.

3. 3
   Leave old accounts alone

   Keep your oldest cards open with a token recurring charge. Age and total available credit both quietly help you every month.

4. 4
   Ration new applications

   Space credit card applications 3–6 months apart, and stop applying entirely 6–12 months before a mortgage.

5. 5
   Check the data once a year

   Pull all three reports free at annualcreditreport.com and dispute anything that isn't yours or isn't right. Errors are common and free to fix.

The bottom line

Your credit score is five inputs, and two of them — on-time payments and low reported balances — are 65% of the grade. Automate the first, manage the second around your statement dates, and let time handle the rest. Everything else is tinkering at the margins.