How we check calculations

Start with the declared model

Each financial tool states how contributions or payments are timed, how interest is compounded and what is excluded. Tax and scheme tools identify their supported year or projection assumptions. An editable rate is a scenario, not a promise that the rate will stay unchanged.

Check examples and boundaries

We compare reference examples with separate arithmetic or equations, then test zero interest, invalid values, supported negative returns and shared links. Loan tests reconcile principal, interest, extra payments and the final balance. Home-loan comparisons keep ownership expenses on the same original time horizon.

Rounding and schedules

Most calculations retain full precision internally and round only for display. Tax calculations and annual scheme interest use the rounding described on their pages. Home-loan CSV files display paise; adding individually rounded rows can differ slightly from the unrounded summary.

Review scope

Calculation examples were checked on September 12, 2026. These are software and mathematical checks; no independent professional financial review is claimed. They do not certify a person’s financial decision or tax filing.

Corrections

Report a reproducible issue. A correction should update the calculation, its tests, its explanation and the checked date together. A rule change needs source verification before the supported scope changes.

Explore the checked tools