CalcCrack Methodology

1. Sources of rate data

Interest rates quoted in loan, deposit, and amortisation calculators are taken from the following published sources. None of them are scraped in real time; each is reviewed on the cadence documented in section 4.

• Reserve Bank of India — repo rate, reverse repo, bank rate, SDF, and MSF quoted from the RBI Monetary Policy Statements and the Database on Indian Economy at rbi.org.in. RBI press releases and master circulars on external benchmark linked lending rates (RBI/2019-20/160 and successors) define how retail loan rates are structured.
• State Bank of India — MCLR, EBLR, base rate, home loan, car loan, personal loan, and fixed deposit card rates quoted from sbi.co.in/web/interest-rates.
• HDFC Bank and ICICI Bank — published retail loan and deposit rates from their respective interest rates pages. These are used for the bank comparison calculators.
• Small Savings rates — PPF, Sukanya Samriddhi, NSC, KVP, SCSS, and POMIS rates taken from the quarterly rate notification published by the Department of Economic Affairs, Ministry of Finance, Government of India.

2. Sources of tax data

Tax calculations reference the following primary documents. Section numbers are quoted on each calculator page where relevant.

• Income Tax Act 1961 — the master statute. Key sections used across calculators include Section 10(13A) for HRA exemption, Section 24(b) for home loan interest deduction, Section 80C for eligible investments, Section 80D for medical insurance, Section 80CCD(1B) for additional NPS deduction, Section 87A for rebate, Section 112A for long-term capital gains on listed equity, Section 111A for short-term capital gains, and Section 115BAC for the new tax regime.
• Finance Act of the relevant year — tax slabs, standard deduction, surcharge thresholds, and cess are updated from the latest Finance Act on the day the budget is passed.
• CBDT circulars and notifications — published at incometaxindia.gov.in. Used for procedural rules, TDS rates, and clarifications (for example, the HRA metro city classification under Circular No. 90/1975 and subsequent clarifications).

3. Sources of scheme data

• PPF Rules 2019 — the Public Provident Fund Scheme 2019 notified in the Gazette of India on 12 December 2019 by the Department of Economic Affairs. Defines contribution limits (Rs 500 minimum, Rs 1,50,000 maximum per financial year), the 15-year lock-in, extension rules, partial withdrawal eligibility from year 7, and loan eligibility between years 3 and 6.
• National Pension System regulations — the PFRDA Act 2013 and the PFRDA (National Pension System Tier II - Optional Account) Regulations 2015, combined with scheme documents published by NSDL (the PRAN-issuing Central Recordkeeping Agency). Defines asset class caps, equity cap for private sector subscribers, annuity purchase requirement at exit, and the 60 per cent tax-free lump sum rule.
• Sukanya Samriddhi Account Scheme Rules 2019 — notified by the Department of Economic Affairs in the Gazette of India. Defines deposit limits, tenure, partial withdrawal at age 18, and closure rules.
• EPF and EPS— Employees' Provident Funds and Miscellaneous Provisions Act 1952 and scheme documents published by the Employees' Provident Fund Organisation.
• Atal Pension Yojana and PMVVY — scheme booklets from the respective administering agencies (PFRDA and LIC).

4. Update cadence

• Bank rates and repo rate: reviewed weekly. Each calculator page carries a "Last verified" date that reflects the most recent review against the RBI and SBI published rate sheets.
• Small savings rates(PPF, SSY, NSC, SCSS): reviewed quarterly, on the day the Ministry of Finance publishes the next quarter's rate notification.
• Tax slabs and Section 80 limits: reviewed annually on Budget Day (1 February) and again when the Finance Act receives presidential assent. Calculators are updated within 48 hours of the Finance Bill being passed.
• Bank comparison calculators: reviewed weekly for rate changes, monthly for fee and product feature changes.

5. Limitations

CalcCrack calculators produce estimates based on published rates and statutory formulas. The following factors are outside the scope of any calculator on this site and will produce a difference between our estimate and your actual outcome.

• Credit score and negotiation: actual retail loan rates vary by the borrower's CIBIL or Experian credit score, employer category, existing relationship with the bank, and negotiation. Published card rates are a starting point, not a quote.
• Processing fees and insurance bundling: the effective cost of a loan is higher than the headline rate once processing fees, documentation charges, and bundled insurance premiums are added. Our EMI calculator shows the rate-only EMI; add 0.5 to 1.5 per cent of the sanctioned amount as a rough processing-fee estimate.
• Stamp duty and registration: these vary by state, by city within a state, and by registrar. Home loan affordability calculators use a representative state estimate; your actual stamp duty must be confirmed with the sub-registrar office.
• Market-linked returns: SIP, mutual fund, and NPS returns depend on future market performance. Projections use an assumed annualised return that you can edit. They are not a forecast.
• Individual tax situations: tax calculators do not model every edge case (for example, clubbing of income, deemed let-out property, gratuity exemption limits for specific employer categories, or NRI taxation under a Double Taxation Avoidance Agreement). Consult a Chartered Accountant for your return.

6. How to verify our numbers

Every rate or formula used on CalcCrack can be cross-checked against a primary source. The short list:

• RBI repo rate and policy corridor: rbi.org.in press releases
• SBI lending and deposit rates: sbi.co.in/web/interest-rates
• Small savings quarterly rates: Press Information Bureau releases from the Ministry of Finance
• Income tax slabs and deductions: incometaxindia.gov.in
• PPF Rules 2019 notification: Gazette of India, Extraordinary, Part II, Section 3, Sub-section (i), dated 12 December 2019

7. Editorial review

8. Corrections

If you find a calculation, rate, or regulatory citation that you believe is wrong, write to hello@calccrack.com with a link to the primary source. Verified corrections are pushed live within 48 hours. The author page lists my credentials and what I am and am not qualified to opine on.