A credit score is a three-digit number, usually between 300 and 850, that summarizes how reliably you've repaid borrowed money in the past. Lenders use it to decide whether to approve a loan and what interest rate to offer. It sounds abstract until you realize it can be the difference between a 6% and a 14% rate on the same car loan.
The five factors that build the number
- Payment history (about 35%) — Do you pay on time, every time? This is the single biggest factor.
- Amounts owed (about 30%) — Mainly your credit utilization: how much of your available credit you're using.
- Length of credit history (about 15%) — Older accounts help, which is why closing your oldest card can quietly hurt your score.
- Credit mix (about 10%) — A mix of credit cards and installment loans (like an auto loan) looks more complete than one type alone.
- New credit (about 10%) — Applying for several accounts in a short window can ding your score temporarily.
The myth that trips up almost everyone
Checking your own credit score does not lower it. This is called a "soft inquiry" and it's invisible to lenders. What does affect your score is a "hard inquiry" — which only happens when you actually apply for new credit, like a loan or a new card.
Utilization: the lever with the fastest effect
Credit utilization is the percentage of your available credit you're currently using. Someone with a $5,000 limit and a $2,500 balance is at 50% utilization — generally considered high. Getting utilization under 30%, and ideally under 10%, tends to move a score faster than almost any other single change, and it can happen within one billing cycle.
What doesn't matter as much as people think
Income is not a factor in your credit score at all — a high earner with missed payments can score lower than a modest earner who pays on time. Your score also isn't affected by rent or utility payments unless you specifically enroll in a reporting service, since those aren't automatically reported the way loans and credit cards are.
Building credit is less about tricks and more about a small set of consistent habits: pay on time, keep balances low relative to limits, and let accounts age. It's slow, unglamorous, and it works.