Your credit score is one of the most influential numbers in your financial life — yet most people have only a vague idea of what it means or how it’s calculated. A difference of 100 points can mean thousands of dollars more in interest over the life of a loan.

What is a credit score?

A credit score is a three-digit number that summarises your credit history. It signals to lenders how likely you are to repay debt on time. The most commonly used model in the US is the FICO score, which ranges from 300 to 850.

Score rangeCategoryLender view
800–850ExceptionalBest rates, near-instant approvals
740–799Very goodExcellent rates, strong approval odds
670–739GoodMost standard products available
580–669FairHigher rates, some restrictions
300–579PoorLikely declined or requires co-signer

What makes up your FICO score?

FICO scores are calculated from five factors, weighted roughly as follows:

  1. Payment history (35%) — This is the most important factor. A single missed payment can drop your score by 50–100 points. Pay every bill on time, every time.

  2. Amounts owed / credit utilisation (30%) — How much of your available credit you’re using. Keeping utilisation below 30% is recommended; below 10% is ideal. A high utilisation ratio signals financial stress.

  3. Length of credit history (15%) — Older accounts help your score. Avoid closing old credit cards even if you don’t use them.

  4. New credit / hard enquiries (10%) — Every time you apply for credit, a hard inquiry is recorded. Multiple applications in a short window look risky.

  5. Credit mix (10%) — Having a variety of credit types (credit cards, instalment loans, mortgage) is slightly positive, but don’t take on debt you don’t need just to diversify.

What lenders actually look for

Your score is a summary, but lenders also examine the underlying data:

  • Derogatory marks: bankruptcies (up to 10 years), foreclosures, collections, and late payments (7 years) are particularly damaging.
  • Debt-to-income ratio: even a great credit score won’t overcome a DTI ratio above 43–50% for mortgage qualification.
  • Employment and income: lenders want stable, documented income. Self-employed applicants typically need 2 years of tax returns.
  • Recent behaviour: a score that’s been improving over the past 12 months is viewed more favourably than a static score.

How to improve your credit score

Fast improvements (1–3 months)

1. Pay down credit card balances. If your utilisation is above 30%, paying it down has an almost immediate positive effect — often within one billing cycle. This is the single fastest way to raise a score.

2. Request a credit limit increase. Increasing your limit while keeping spending constant lowers your utilisation. Do this on accounts where you’ve had a good history.

3. Dispute errors on your credit report. Studies suggest around 20–25% of credit reports contain errors. Get your free report at annualcreditreport.com (US) and dispute any inaccuracies with the relevant bureau.

4. Become an authorised user. If a family member has a long-standing, well-managed credit card, being added as an authorised user can add their positive history to your profile.

Medium-term improvements (3–12 months)

5. Set up automatic payments. The single most effective thing for your payment history — never miss a bill again. Set autopay for at least the minimum payment on every account.

6. Keep old accounts open. Closing an old card reduces your available credit and can shorten your average account age.

7. Space out new applications. If you need to apply for new credit, do so strategically and avoid multiple applications in a short period.

Longer-term improvements (1–2+ years)

8. Build a track record. There’s no substitute for time. A consistent pattern of on-time payments over 12–24 months significantly improves your score.

9. Manage instalment loans carefully. Paying down a car loan or mortgage builds positive history. Making extra payments reduces the balance and the interest you pay.

How credit scores affect your finances

The stakes are high. Using a 30-year $300,000 mortgage as an example:

Credit scoreApproximate rateMonthly paymentTotal interest paid
760+6.25%$1,848$365,280
700–7596.75%$1,945$400,200
640–6997.50%$2,098$455,280
580–6398.25%$2,254$511,440

The difference between a 760+ score and a 640 score: $146,000 in extra interest over the life of the loan — more than the original loan amount in extra payments.