Your credit score feels like a black box, but the FICO formula — used in the vast majority of lending decisions — is actually well documented. Here's what's really behind the number.
The five factors, ranked by weight
| Factor | Weight | What actually helps |
|---|---|---|
| Payment history | 35% | Paying on time, every time — one 30-day-late mark can matter more than any other single action |
| Amounts owed (utilization) | 30% | Keeping revolving balances low relative to your limits |
| Length of credit history | 15% | Time — this is why closing your oldest card can quietly hurt you |
| Credit mix | 10% | Having both revolving (cards) and installment (loans) accounts |
| New credit | 10% | Not opening several accounts in a short window |
Score ranges and what they mean
- 800–850: Exceptional — best available rates on nearly everything
- 740–799: Very good — qualifies for most premium rates
- 670–739: Good — the FICO-defined baseline for "good" credit
- 580–669: Fair — approvals possible but with higher rates
- Below 580: Poor — approvals harder, often requiring secured products first
Common myths, debunked
"Checking my own score hurts it"
False. Checking your own score or report is a soft inquiry and has zero impact. Only hard inquiries from lenders when you formally apply for credit have any effect, and it's small and temporary.
"Carrying a small balance helps my score"
False. Paying your statement balance in full every month is fine and actually ideal — utilization is measured off the reported balance regardless of whether you carry it or pay it off, so there's no benefit to carrying interest-bearing debt on purpose.
"Closing old cards improves my score"
Usually false. Closing a card can raise your utilization ratio (less total available credit) and eventually shorten your average account age — both can lower your score.
Why your score can differ across apps and bureaus
There isn't one universal score. FICO alone has multiple versions, plus VantageScore as a separate model, and each of the three bureaus can hold slightly different information — which is exactly why checking all three reports (not just one score from one app) matters when you're troubleshooting.
Next step
See the full credit repair guide for the step-by-step process to act on this.