How Credit Scores Work — the Five Factors, Weighted by What Actually Moves Them
Your score is five factors in fixed proportions — but they move at wildly different speeds. Knowing which lever moves in days versus years is the difference between a rebuild plan and guesswork.
The five factors — the map
FICO weighs: payment history 35%, amounts owed/utilization 30%, length of history 15%, credit mix 10%, new credit 10%. VantageScore orders slightly differently but the practical map holds. The weights are fixed; your position inside each is not. A thin file and a damaged file can have identical weights and completely different problems.
Payment history (35%) — the slow, unforgiving one
Every on-time payment adds a data point; every 30+ day late sticks up to 7 years. One late on a clean file can cost 60-110 points; on a thin file, more. The asymmetry is brutal: you cannot "bank" extra on-times to offset a late — the late IS the history for years. Defense: autopay minimums on everything, even spend-only cards. Offense: nothing beats simply never missing one. This factor is why rent reporting (BoomPay) is so valuable — it converts a bill you already pay into 12-24 on-time data points.
Utilization (30%) — the fast, forgiving one
Snapshot-only, no memory, fully controllable in 30 days. Under 10% reported is optimal; 30% is the ceiling of acceptable. Pay before statement date and even a $49 line reports clean. After a late payment, this is the first lever to pull — and unlike history, recovery is total. Our utilization guide covers the mechanics in depth.
Length of history (15%) — the one you cannot buy
Average age of all accounts, plus the age of your oldest. Starts earning the moment your first tradeline reports; meaningful at 1-2 years, strong at 5+. The classic self-inflicted wound: closing your oldest card. Keep old no-fee cards alive with one small recurring charge. For newcomers this factor simply starts at zero — Zolve reporting from month 1 is the whole game.
Credit mix (10%) — a small factor with outsized signaling
A file with one revolving card and one installment account (builder loan) signals more than two cards. It is why the card + Self/Credit Strong combination outperforms either alone. Do NOT open an installment product just for mix if payments strain your budget — a missed installment payment hits the 35% factor and erases the mix benefit.
New credit (10%) — inquiries and account density
Each application is a hard inquiry (small, fading in 12 months) — but several in a short window signals risk far beyond their weights, especially on thin files. Rate-shopping windows exist for auto/mortgage; credit cards have none. Rule: one application at a time, spaced 3+ months, and only when utilization is low and reported clean.
What to fix first — the decision order
1. Anything late reporting: fix the cause before anything else. 2. Utilization over 10%: pay before statement — 30-day payoff. 3. No installment account: add a builder loan — 60-90 days to report. 4. No rent tradeline: add BoomPay. 5. Then: time. This order is exactly what our quiz scores — the plan generator turns it into a month-by-month schedule.
Related guides
- Issuer Policy Tracker — dated verification
- How long does building credit take?
- Credit utilization explained
- When does a secured card graduate?
- Secured card vs credit-builder loan
- Deposit strategies on a tight budget
- Build credit without a card
- Denied a card? Next steps per reason
- New to the US? SSN / ITIN / passport tree
- Rebuilding after bankruptcy