Credit score · Chapter 02 of 08

How it is calculated

Bureaus describe the inputs to their models but never the weights, so anyone quoting “30% payment history” is guessing. What is public, consistent and worth acting on is the list of inputs — and the fact that RBI makes every bureau use the same 300–900 scale.

Core · 8 min read · reviewed 2026-09-23

Section 1

What the RBI fixes, and what the bureaus decide

Fixed by RBI: the scale. Scores “shall be calibrated from 300 to 900 by all CICs, so that they have a common classification of credit scores”.
Left to each bureau: the model, the inputs and their weights, and the cut-offs it publishes for its own bands.
Also left to lenders: whether they even use the score, and what score they require for a given product.

Section 2

CIBIL's four key factors

Payment history — late payments and defaults on EMIs pull the score down.
Credit mix — a balance of secured (home, auto) and unsecured (personal loan, credit card) debt reads better than an unsecured pile.
Multiple enquiries — a run of loan enquiries suggests your debt burden is about to rise.
High credit utilisation — using a large share of your card limits suggests debt is already rising.

Section 3

Experian lists the same story with two more inputs

Payment history, credit utilisation and credit age (how long your accounts have been open).
Credit type (the mix) and total credit accounts, plus the recency of applications.
The practical reading of all of this: repay on time, use a modest share of your limits, keep accounts old, and do not apply for credit in bursts.

Section 4

Why the number is not reproducible

The scoring model is proprietary and versioned — bureaus change it, and the same report can score differently after a model update.
Your three bureaus hold partly different data, because each lender submits to each bureau on its own timetable.
Reconstructing the score from a report is therefore a judgement, not arithmetic. Track the report's contents, not a spreadsheet of the score.

Key takeaways

RBI fixes the 300–900 scale; the four bureaus each own their own model and weights.
Payment history and credit utilisation are where real damage happens — and both are fixable.
No published weighting exists, so ignore any article that prints percentages as fact.

Common mistakes

Believing a specific percentage weight for any factor — no bureau publishes one.
Closing your oldest card to “tidy up” and losing account age.
Applying to several lenders in one week to shop for a rate and stacking enquiries.

Questions

Is payment history really the biggest factor?

Bureau guidance treats it as the dominant input, but none of them publishes a weight. What is certain is that missed EMIs and defaults are the fastest way to damage a score, so treat repayment as the priority regardless of the exact share.

Does my income affect the score?

Not directly. Bureaus score credit behaviour, not earnings. Income matters at the lender, which weighs it alongside the score and its own affordability rules — so a high earner can still carry a poor score and vice versa.

Why is my score different at two bureaus in the same month?

Because each lender reports to each bureau on its own reporting cycle and the bureaus update on their own schedules. Until the RBI's four-reference-date regime (in force since 1 July 2026) fully settles across lenders, small month-to-month differences between bureaus are normal.

Do enquiries from shopping around for a loan count?

Yes — a lender enquiry appears on the report. Bureau guidance is to apply for new credit in moderation; a cluster of applications in a short window reads as someone taking on more debt.

Glossary

Credit Score Credit Utilisation Ratio Hard Enquiry

Guides

How to improve your credit score

Payment history, utilisation, mix and age — the levers bureau guidance names, and realistic timelines.

Educational, not advisory — and never a score-fixing service. LetsInvest is a research publication, not a credit bureau, lender or SEBI-registered investment adviser, and we do not check credit scores ourselves. Corrections and disputes are free at every bureau, nobody can legitimately sell you a higher score, and no page here asks for your PAN. Confirm anything that matters against the RBI directions and the bureau's own site before you act.

Sources

Reviewed 23 Sept 2026. Rules change — the RBI directions and each bureau's own pages are the authority, and this hub links straight to them.

RBI — Master Direction – Reserve Bank of India (Credit Information Reporting) Directions, 2025 (6 Jan 2025)300–900 calibration across CICs, the free full credit report (once a year), the 30-day correction rule and ₹100/day compensation, access alerts, dispute flags on the CIR, and the ban on reporting declined applications.
TransUnion CIBIL — “All You Need To Know About Your CIBIL Score And How It Is Calculated”CIBIL's score range, its four key factors (payment history, credit mix, multiple enquiries, high credit utilisation), its improvement tips and the 79%-above-750 figure.
Experian India — Consumer Services (score range, factors, grievance levels)Experian India's 300–900 range, its factor list, its unauthorised-enquiry guidance and its Level 1/2/3 grievance escalation contacts.
RBI — Credit Information Reporting Amendment Directions, 2025 (notification 13188, 4 Dec 2025; in force 1 Jul 2026)The move to four reporting reference dates (9th, 16th, 23rd and last day of the month) with submission windows after each.

← All credit-score chapters

How it is calculated

What the RBI fixes, and what the bureaus decide

CIBIL's four key factors

Experian lists the same story with two more inputs

Why the number is not reproducible

Key takeaways

Common mistakes

Questions

Go deeper

Sources

How it is calculated

What the RBI fixes, and what the bureaus decide

CIBIL's four key factors

Experian lists the same story with two more inputs

Why the number is not reproducible

Key takeaways

Common mistakes

Questions

Go deeper

Sources