Your credit score follows you through almost every major financial decision: mortgage applications, car loans, rental agreements, and sometimes even job applications. Yet most people have only a vague sense of what actually determines that three-digit number.
The average American credit score reached 717 in 2025, according to Experian. Millions still sit below 670, the threshold most lenders consider fair, paying interest rates 2% to 5% higher than borrowers above 740. On a $300,000 mortgage, that rate gap costs $80,000 to $150,000 over 30 years.
The 5 FICO Score Factors and Their Exact Weights
FICO credit scores used by 90% of top lenders are calculated using five factors: payment history 35%, amounts owed (credit utilisation) 30%, length of credit history 15%, credit mix 10%, and new credit inquiries 10%. Payment history and utilisation together account for 65% of your score, making them the two highest-leverage areas. A single missed payment can drop a good score by 60 to 110 points, while reducing utilisation below 10% can add 20 to 40 points within one billing cycle.
| FICO Factor | Weight | What It Measures |
|---|---|---|
| Historique des paiements | 35% | Whether you pay bills on time the most important factor |
| Amounts Owed (Utilisation) | 30% | How much of your available credit you are using |
| Durée de l'historique de crédit | 15% | Average age of all your accounts |
| Crédit Mix | 10% | Variety of credit types: cards, loans, mortgage |
| New Credit Inquiries | 10% | Recent applications for new credit accounts |
Factor 1: Payment History (35%) The Biggest Driver
Payment history is the single most weighted FICO factor at 35%. It records whether you have paid every credit account on time. A payment 30 or more days late is reported as a delinquency and can drop a 750 score by 60 to 110 points. Payments under 30 days late are typically not reported. Once a delinquency is reported, it remains on your credit report for 7 years, though its impact diminishes significantly after 2 years of consistent on-time payments following the missed event.
- One missed payment 30+ days late can drop a 750 score by 60 to 110 points
- A 90-day late payment causes more damage than a 30-day late payment
- Delinquencies stay on your report for 7 years but fade after 2 years of clean payments
- Setting up autopay for at least the minimum payment prevents this damage entirely
From experience: A freelance photographer’s score dropped 74 points in one month. She had never intentionally missed a payment but a billing address change sent statements to her old address. A card went 35 days past due before she discovered it. One administrative error triggered a major scoring event. We filed a goodwill adjustment request with the issuer (partially successful) and set up autopay immediately. Her score recovered to within 12 points of the original within 14 months.
Factor 2: Credit Utilisation (30%) The Fastest to Change
Credit utilisation measures total credit card balances divided by total credit card limits. The recommended rate for a high score is below 30%, with below 10% producing optimal results. Someone with a $10,000 total limit should keep balances under $3,000 for good scores and under $1,000 for excellent scores. Utilisation is recalculated monthly when balances are reported paying down balances can raise your score within one billing cycle, making it the fastest-moving factor in the FICO model.
| Utilisation Rate | Score Impact | Example ($10K limit) |
|---|---|---|
| Under 10% | Excellent | Balance under $1,000 |
| 10% to 30% | Good | Balance $1,000 to $3,000 |
| 30% to 50% | Moderate negative | Balance $3,000 to $5,000 |
| 50% to 75% | Significant negative | Balance $5,000 to $7,500 |
| Above 75% | Severe negative | Balance above $7,500 |
From experience: A small business owner used his personal credit card for business expenses, routinely running the balance to 80% before paying in full. He never paid late or paid interest but his score stuck around 640. He needed 680 for a business loan. We solved it in 60 days: he requested a limit increase (instantly reducing his utilisation percentage) and switched to paying the balance twice monthly. His score reached 694 without changing any other habit.
Factor 3: Length of Credit History (15%)
Credit history length accounts for 15% of your FICO score. It measures the age of your oldest account, the average age of all accounts, and how long since each account was last used. The optimal average account age is typically 7 or more years. Closing old credit cards shortens your average account age and simultaneously increases your overall utilisation rate making it one of the most damaging actions you can take to an otherwise healthy credit profile.
- Closing your oldest card reduces history length and increases utilisation simultaneously
- Opening multiple new accounts rapidly lowers your average account age
- Inactive accounts may be closed by the issuer use old cards occasionally to keep them active
Factors 4 and 5: Credit Mix (10%) and New Credit (10%)
Credit mix measures whether you have experience managing different types of credit: revolving accounts (credit cards) and installment loans (auto, student, personal, mortgage). New credit inquiries account for 10% each hard inquiry from an application typically reduces your score by 5 to 10 points for up to 12 months. Multiple mortgage or auto loan inquiries within a 14 to 45 day window are treated as a single inquiry by FICO, recognising that consumers shop for rates.
| Inquiry Type | Score Impact | Examples |
|---|---|---|
| Hard inquiry | 5 to 10 points for up to 12 months | Credit card, mortgage, auto, personal loan applications |
| Soft inquiry | Zero score impact | Checking your own score, employer background check, pre-approval offers |
Foire aux questions
Q: How fast can I improve my credit score?
A: The fastest improvement comes from reducing credit utilization; this can raise your score within one billing cycle (30 to 45 days). Paying down a maxed-out card can produce 20 to 50 point gains. Payment history improvements take 6 to 12 months of consistent on-time payments to meaningfully offset past delinquencies. Use the Calculateur de score de crédit Chez ToolsTechnique, modélisez votre parcours d'amélioration.
Q: Does checking my own credit score hurt it?
A: No. Checking your own score is a soft inquiry with zero score impact. You are entitled to one free credit report per year from each bureau (Equifax, Experian, and TransUnion) at annualcreditreport.com. Many card issuers also provide free monthly FICO score access through their apps.
Q: Does closing a credit card hurt my score?
A: Usually yes, it reduces available credit (raising utilization) and may shorten credit history length. If you must close a card, close your newest card with the lowest limit, not your oldest or highest-limit account.
Q: How much does a missed payment drop my score?
A: The impact depends on your starting score. A 750 score can drop 60 to 110 points from one 30-day late payment. A 680 score drops 40 to 70 points. Higher scores fall further because they have more to lose. Most scoring impact fades within 2 years of returning to on-time payments.
Q: What credit score do I need for a mortgage?
A: Conventional mortgages typically require a minimum 620 FICO. FHA loans allow 580 with 3.5% down. The best rates go to borrowers with 740 or above. Per the CFPB, a 100-point score difference can change your mortgage rate by 0.5% to 1.5%, costing tens of thousands over 30 years.
Start Improving Your Score Today
The two highest-impact actions: set up autopay on all accounts and pay down any card above 30% utilization. Those two moves address 65% of your total FICO score.
Use the free Calculateur de score de crédit at ToolsTechnique to estimate your current score factors, then use the Calculateur de remboursement de dette to build a balance paydown plan that reduces utilization as fast as possible.
