Sources
We use primary sources wherever possible: tax authorities and finance ministries (for example the IRS, HMRC, ATO and India’s CBDT and GST Council), regulators (such as RBI, SEBI, IRDAI and CMS), standards bodies (NEC, IRC, IS codes) and official exam notifications. Secondary sources are used only to cross-check.
How tools are built
- Each calculator’s formula is written once in code and reused by the page, so the explanation and the result always match.
- Automated tests (140+) check formulas against worked examples and official tables; browser acceptance tests check that every tool type works.
- Where official sources disagree or a value could not be verified, the page shows a clear warning instead of guessing.
Page variants
Some tools have pages for common inputs (for example a specific loan amount). These help visitors land on a ready-made answer; to avoid duplicate content, such variants are excluded from search indexing and show the same verified calculator as the main page.
Use of automation and AI
Page layouts are generated from structured data, and some explanatory text and practice questions were drafted with the help of AI tools. Formulas are implemented and tested in code, factual question banks are limited to stable, well-established facts, and the publisher reviews content before it is published.
Updates and corrections
Rates and rules are reviewed when authorities announce changes (for example each budget or financial year). Pages show the rules they use and when they apply. Report an error at support@pgento.com; verified corrections are published promptly.
Last updated: 12 November 2026