Methodology
How our calculators work
Each calculator on Calculator Hub uses a documented, standard formula appropriate to the calculation — for example, the reducing-balance EMI formula for loans, the compound interest formula for fixed-tenure deposits, and the statutory formula for gratuity. The formula used on each page is shown in that page's "How the calculation works" section.
Configurable rates
Where a calculation depends on a rate or rule that is set by the government or an external body and can change over time — income tax slabs, EPF/PPF interest rates, gratuity ceilings, professional tax slabs — that value is stored in an admin-editable setting rather than fixed in code. Each such page shows a "last updated" date for the configured rate.
Assumptions
Calculators that model future outcomes (SIP, lumpsum, SWP, salary projections) rely on assumptions you provide, such as an expected rate of return. These are illustrative inputs, not predictions, and actual results can differ significantly, particularly for market-linked instruments.
Limitations
Our calculators handle the common, general case for each topic. They may not capture every edge case, regional variation (e.g. state-specific professional tax), or individual circumstance. Each calculator page lists specific limitations under "Important considerations."
References
Where applicable, each calculator links to the official government or regulatory source for the rate or rule it uses.