Methodology

How we select formulas

Every calculator on MyCalculator uses standard, widely accepted formulas for its category — for example, the reducing-balance amortization formula for loans and EMI, the Mifflin-St Jeor equation for BMR, and the US Navy circumference method for body fat estimation. We don't invent proprietary formulas; where a field has an established standard method, we use it and say so on the calculator page.

How we handle assumptions

Generic calculators (salary, EMI, electricity cost, and similar) are built to work with any currency and any country's numbers — you supply the figures, we do the math. We do not bake in country-specific defaults (like a fixed electricity rate or a specific tax bracket) into generic tools. Where an assumption is unavoidable — like a standard Monday–Friday work week for the working days calculator — it's stated directly on that calculator's page.

How country-specific rules are handled

Where local rules genuinely change the answer — like income tax or take-home pay — we build separate, dedicated calculators under International rather than folding assumptions into generic tools. Each of those pages states its data source, the tax year or rule period it reflects, and its limitations.

Rounding

Currency results are typically shown to 2 decimal places; other numeric results use a precision appropriate to the field (e.g. percentages to 1–2 decimals, ratios and fractions in simplified whole-number form).

Updates

Formulas are standard and rarely change. Country-specific figures (tax bands, rates) are reviewed periodically and updated when official sources change; each country page states the period it reflects.

Limitations

All calculators on this site provide estimates for general informational purposes. They are not a substitute for advice from a qualified financial, tax, legal or medical professional. See our disclaimer for full detail.