Calculation methodology
A result should be understandable, reproducible and honest about its limits.
One formula implementation
Interactive results, default worked examples and the guide scenarios use the same calculation functions. The site generates its initial HTML from those functions, so examples can be reproduced in the tool. Each calculator states its contribution timing, rate convention and major exclusions.
Checks performed
On 29 October 2026, software checks covered all 55 default scenarios, selected zero- and negative-return cases, tax rebate boundaries, zero-interest EMIs, amortization accounting, INR conversions, XIRR date validation and ambiguous cash flows. Browser checks cover tool operation, input validation, shared links, money words and responsive layouts. These are engineering checks, not a professional review of every financial situation.
Rates, dates and tax scope
Tax tools identify FY 2026–27 and their resident, age and ordinary-income limits. They exclude special-rate income and surcharge. Small-savings pages label the period behind their default rates and let you change the assumption. A content publication date is separate from a rate’s effective period.
Reference links were checked during the site’s preparation on 29 October 2026. Rates are not refreshed automatically; use the source applicable to your actual transaction or filing date.
Rounding and model differences
Most displayed money totals are rounded to whole rupees. Tools involving paise or per-unit costs preserve their stated precision. Internal calculations retain greater precision where appropriate. Lender day counts, statement conventions, fees and actual investment paths can produce different outcomes.
Source hierarchy and corrections
Tax and scheme explanations use the official sources linked from the relevant tools where available. General mathematical tools state their formulas directly. When an issue is reported, the correction should include the affected assumptions, a reproducible case and an appropriate regression check.