The Five Factors Behind Your FICO Score
Your FICO credit score isn't a mystery—it's calculated from five specific factors, each weighted differently. Understanding what affects your credit score gives you the power to improve it strategically rather than hoping for random improvement over time.
| Factor | Weight | What It Measures |
|---|---|---|
| Payment History | 35% | Whether you pay bills on time |
| Credit Utilization | 30% | How much of your credit limit you're using |
| Length of Credit History | 15% | How long you've had credit accounts |
| Credit Mix | 10% | Variety of credit types you carry |
| New Credit | 10% | How recently you've applied for new credit |
Payment History: The Single Biggest Factor (35%)
Payment history is the largest factor in your credit score. A single 30-day late payment can drop an excellent credit score (780+) by as much as 90–110 points. For someone with a lower score, the impact is less severe—but still significant.
What matters here:
- On-time payments build your score consistently over time
- Late payments (30, 60, 90+ days) are reported to bureaus and stay on your report for 7 years
- Collections, charge-offs, and bankruptcies are the most damaging marks possible
- Positive payment streaks of 12–24 months can significantly lift your score
The key takeaway: even if you can only make the minimum payment, make it on time every single month.
Credit Utilization: The Fastest Factor to Change (30%)
Credit utilization is the ratio of your current credit card balances to your total credit limits. If you have a $10,000 total credit limit and carry $3,000 in balances, your utilization is 30%.
Most credit experts recommend keeping utilization below 30%, and the best scores typically show utilization under 10%. Unlike payment history, utilization can change dramatically in 30 days—just by paying down balances before your statement closes.
- Utilization above 70% is very damaging to your score
- Each credit card's individual utilization matters, not just the overall total
- Requesting a credit limit increase (without spending more) instantly improves utilization
Length of Credit History, Credit Mix, and New Credit
Length of Credit History (15%): The average age of all your accounts and the age of your oldest account both count. Closing old credit cards reduces your average account age. Someone with a 15-year-old credit card they never use is still benefiting from it every month.
Credit Mix (10%): Lenders like to see that you can handle different types of credit responsibly. A mix of revolving credit (credit cards, HELOCs) and installment credit (auto loans, mortgages, student loans) is ideal. You don't need to take on debt just to diversify, but it's worth knowing this factor exists.
New Credit (10%): Every time you apply for credit, a hard inquiry appears on your report. Each hard inquiry can lower your score by 5–10 points temporarily. Multiple applications in a short window (rate shopping for a mortgage or auto loan) are typically treated as a single inquiry if done within 14–45 days depending on the scoring model.
What Does NOT Affect Your Credit Score
Several common misconceptions exist about credit scores. The following do not directly impact your FICO score:
- Your income or employment status
- Your bank account balances
- Checking your own credit score (soft inquiries)
- Your age, race, gender, or national origin
- Interest rates on your existing accounts
- Utility bills (unless they go to collections)
However, services like Experian Boost and rent-reporting programs can add positive payment history for utilities and rent, which may lift your score.
Frequently Asked Questions
What is the most important factor in a credit score?
Payment history is the most important factor, making up 35% of your FICO score. Even one 30-day late payment can significantly lower your score.
Does checking your credit score lower it?
No. Checking your own credit score is a soft inquiry and does not affect your score at all. Only hard inquiries from lenders when you apply for credit can temporarily lower your score.
How quickly can I improve my credit score?
Paying down credit card balances can improve your score within 30 days since utilization updates monthly. Building payment history improvements takes 6–12 months of consistent on-time payments.