Accuracy you can verify
Every formula is implemented directly from official sources — Income Tax Department slabs, GST Council rates, and standard mathematical formulas — and every calculation function is tested against known values before deployment. Wherever rules vary by employer, state, or lender, the page documents the exact assumptions used so you can verify the result yourself.
Testing methodology
Unit tests
Every calculation function has automated tests covering normal cases, edge cases, and boundary conditions.
Verified formulas
Formulas sourced from official government publications, financial regulations, and mathematical standards.
Manual verification
Each calculator output is manually verified against known results before launch and after each update.
What we test
- →EMI formula matches the standard amortization formula E = P × r × (1+r)ⁿ / ((1+r)ⁿ - 1)
- →Income tax calculations match current FY 2026-27 (and FY 2025-26) official tax slabs for Old and New Regimes
- →GST calculations follow CGST + SGST / IGST rules as per GST Act
- →SIP/compound interest calculations use the standard future value formula
- →FD maturity amounts use the compound interest formula with quarterly compounding
Reporting issues
If you find a calculation error, please report it immediately to hello@calcbit.in. We investigate and resolve accuracy issues promptly, and note the official source behind every fix.