What factors affect my credit score the most?

FICO scores are calculated using five factors: payment history (35%) — whether you pay on time — is the most important; credit utilization (30%) — how much of your available revolving credit you are using; length of credit history (15%) — how long your accounts have been open; credit mix (10%) — having different types of credit (cards, auto loans, mortgage); and new credit (10%) — recent applications and new accounts. Missing even a single payment can drop your score significantly. Keeping utilization below 30% and having long-standing accounts in good standing are the most consistent drivers of strong scores.