How we build our calculators

How we make sure every calculator on vBlogger is accurate, genuinely useful and honest about its limits.

1. Every calculator solves a real question

We build a calculator only when it answers a decision someone actually faces, such as "Should I prepay my home loan?" or "What price covers my costs?". We don't publish thin pages that repeat another tool with a different name.

2. Formulas follow Indian practice

We match the conventions used by Indian banks, fund houses and government schemes: SIP instalments at the start of each month, quarterly compounding for FDs and RDs, yearly compounding for PPF with deposits by 5 April, the EPF/EPS split, and the current income tax slabs, rebate and marginal relief. Where a simplification is unavoidable, the page says so.

3. The formula is always shown

Each calculator page shows the formula or method, a worked example and the assumptions. The worked example on each page is generated by the same code that runs the calculator, so the text and the tool always agree.

4. Testing before publishing

Every calculator is tested against independent results: published scheme tables, bank calculators and hand calculations, including edge cases like zero interest, very long tenures and payments too low to repay a loan.

5. Rates and rules are reviewed every quarter

Government scheme rates are announced quarterly, and tax rules change with each Budget. We review all rate-dependent pages at least every quarter and whenever rules change, and update the "Reviewed" date on each page. Current review: 27 September 2026 (scheme rates for July–September 2026, tax year 2026-27).

6. Written by people, checked by people

Explanations are written and checked by Viraj Sarfare. We may use software tools to help draft or check text, but every page is reviewed by a person for accuracy and usefulness, and nothing is published automatically in bulk.

7. Official sources

We rely on primary sources: the Income Tax Department, CBIC and the GST portal, EPFO, PFRDA, India Post and the National Savings Institute, RBI and AMFI. Pages link to them wherever relevant.

8. Independence

We're funded by ads and optional premium templates. No advertiser, bank or fund house can pay to change a calculator, a result or our content.

9. Corrections

If you find an error, tell us. We investigate every report, fix confirmed errors promptly and note the update date on the page.