What is a FICO Score?
A FICO Score is a three-digit US credit score ranging from 300 to 850, produced by Fair Isaac Corporation from data in your Equifax, Experian, and TransUnion credit reports. It is calculated from five weighted factors and is used by about 90 percent of major US lenders to underwrite mortgages, auto loans, credit cards, and personal loans.
Detailed definition
Fair Isaac Corporation (FICO) introduced the first generic credit risk score in 1989, replacing the bespoke scorecards lenders previously built in-house. The score is a statistical model trained on millions of bureau records that estimates the probability a borrower will become 90+ days delinquent on any credit obligation in the next 24 months. The model converts that probability into a three-digit number on the 300 to 850 scale, with higher numbers meaning lower risk.
The factor mix is fixed and public: payment history (35 percent of weight), amounts owed including revolving utilization (30 percent), length of credit history (15 percent), new credit and recent hard inquiries (10 percent), and credit mix across revolving and installment accounts (10 percent). The weights are not literal: a thin-file consumer with no installment loan is not penalised the full 10 percent of "credit mix"; the model adjusts dynamically based on what data is present. Income, employment, savings, race, sex, age, and address are not inputs (the Equal Credit Opportunity Act prohibits most of them).
There is no single FICO score. Each of the three US bureaus (Equifax, Experian, TransUnion) holds slightly different data, so each produces its own bureau-specific FICO. On top of that, FICO sells industry-specific variants tuned for auto lending, bankcards, and mortgage; each can score the same file differently. Mortgages still use older versions (Equifax Beacon 5.0, Experian Fair Isaac Risk Model V2, TransUnion FICO Risk Score Classic 04) because Fannie Mae and Freddie Mac standardised on them years ago. Consumer-facing apps usually show FICO 8 or FICO 9, which can be 10 to 30 points higher than the mortgage-pull scores on the same file.
Formula (weights, not a closed-form equation)
FICO score = weighted contribution of five factors, scaled 300 to 850 Payment history 35% Amounts owed 30% Length of history 15% New credit 10% Credit mix 10%
- Payment history = on-time vs late payments, severity (30 / 60 / 90+ days), collections, charge-offs, bankruptcies, foreclosures. A single 30-day late can drop a 780 FICO by 60 to 110 points.
- Amounts owed = total debt and revolving utilization (balances divided by limits). Both per-card and aggregate utilization matter; under 10 percent is the FICO-optimal zone.
- Length of credit history = age of oldest account, average age, and time since most recent account. Closing an old card lowers average age and can lower the score.
- New credit = recent hard inquiries and newly opened accounts. Multiple mortgage or auto inquiries within a 14 to 45 day window count as one (rate-shopping rule).
- Credit mix = the presence of both revolving (cards, HELOC) and installment (mortgage, auto, student) tradelines. Helpful but small; do not open new accounts just for mix.
Worked example (2026)
Consider a US consumer applying for a mortgage in 2026. Equifax data shows:
- Payment history: 100 percent on-time across 8 years, no collections. Strong contributor.
- Amounts owed: 4 credit cards with combined $35,000 limit and $8,400 balance (24 percent overall utilization, one card at 65 percent). Moderate hit from the high-utilization card.
- Length of history: oldest account 11 years, average age 6.5 years. Strong contributor.
- New credit: 2 hard inquiries in the past 12 months for an auto refinance and a credit card application. Mild drag.
- Credit mix: cards + auto loan + mortgage in history. Balanced; full marks.
- Mortgage FICO (Equifax Beacon 5.0): 742. Same file scored on FICO 8 (the consumer-app version): 762.
FICO vs VantageScore
Two scoring companies dominate US consumer credit risk. Both publish on the 300 to 850 scale, but they treat data differently and are used in different settings.
| Attribute | FICO | VantageScore |
|---|---|---|
| Owner | Fair Isaac Corporation | Joint venture of Equifax, Experian, TransUnion |
| Scale | 300 to 850 | 300 to 850 (since version 3.0) |
| Used by | About 90 percent of major US lenders for underwriting | Widely used by free consumer apps; growing in lender use |
| Minimum file | 6 months of history and at least one tradeline reported in the last 6 months | 1 month of history with at least one open or reported tradeline |
| Late-payment penalty | Heavy and lasts 7 years | Slightly more forgiving past 30 days; lighter weight on medical debt |
| Rate-shopping window | 14 to 45 days (varies by version) | 14 days |
| Score bands | 300-579 Poor, 580-669 Fair, 670-739 Good, 740-799 Very Good, 800-850 Exceptional | 300-579 Very Poor, 580-669 Fair, 670-739 Good, 740-799 Very Good, 800-850 Excellent |
Related terms
Related calculators on 3Tej
Once you know your FICO, plug it into these free calculators to see how it shapes rate offers and affordability:
Frequently asked questions
What is a good FICO score?
FICO publishes five score bands on the 300 to 850 scale: 800 to 850 Exceptional, 740 to 799 Very Good, 670 to 739 Good, 580 to 669 Fair, and 300 to 579 Poor. A FICO of 740 or above usually unlocks the best advertised mortgage and auto-loan rates; 670 to 739 still qualifies for most prime credit; below 670 starts to carry rate or approval penalties.
How is a FICO score calculated?
Five factors with fixed weights: payment history 35 percent, amounts owed (utilization) 30 percent, length of credit history 15 percent, new credit and recent inquiries 10 percent, and credit mix 10 percent. Fair Isaac trains the underlying scorecard on bureau-supplied tradeline data, so each of your Equifax, Experian, and TransUnion FICO scores can differ by a few points based on what each bureau holds.
How often does my FICO score update?
Whenever new data hits your credit file at the bureau that produces the score. Most lenders report monthly, on or around the statement closing date, so a meaningful change (paid balance, new account, late payment) typically shows up in your FICO within 30 to 45 days. The score itself is recomputed on demand when a lender pulls it; there is no fixed daily refresh.
Does checking my own credit hurt my FICO?
No. Pulling your own score or credit report through myFICO, AnnualCreditReport.com, your card issuer, or a free monitoring service is a soft inquiry and does not affect FICO. Hard inquiries (when you apply for new credit) typically cost 0 to 5 points and fade in about 12 months even though they remain on the report for 2 years.
What is the difference between FICO and VantageScore?
Both are 300 to 850 credit-risk models, but they are produced by different companies (Fair Isaac vs the three credit bureaus' joint venture) and weight factors differently. VantageScore can score consumers with thinner files (just 1 month of history) where FICO usually needs 6 months and one tradeline reported in the last 6 months. FICO is used by roughly 90 percent of major US lenders; VantageScore is widely used by free consumer apps.
How can I improve my FICO score quickly?
The fastest legitimate moves are paying down revolving balances (target individual card utilization below 30 percent and overall under 10 percent), correcting any reporting errors via dispute, avoiding new credit applications for 6 to 12 months, and ensuring all payments are on time. These changes can lift a score by 20 to 60 points within 60 to 90 days.
Sources and further reading
- myFICO, What's in My FICO Scores? - the official factor breakdown.
- Consumer Financial Protection Bureau, What is a credit score?.
- CFPB, FICO vs non-FICO credit scores.
- VantageScore Solutions, How VantageScore differs from FICO.
- Fannie Mae, Selling Guide B3-5.1-01: General Requirements for Credit Scores - mortgage FICO versions.