Methodology

How our calculators are built

Every calculator on Calqora is built around a well-established, publicly documented formula - such as the standard loan amortization formula, the Mifflin-St Jeor BMR equation, or the standard ROI formula used across finance and marketing. We do not invent proprietary formulas or use "black box" methods.

Formula review process

Each calculator's core logic lives in a dedicated, testable code module with its own automated unit tests covering normal values, zero values, boundary values, and invalid inputs. Formulas are reviewed against reference examples before a calculator is published.

Rounding and units

Currency results are rounded to the nearest cent. Percentages are typically shown to one or two decimal places. Where a calculator supports both imperial and metric units, conversions use standard conversion factors (for example, 1 inch = 2.54 cm, 1 pound = 0.453592 kg).

Assumptions and limitations

Every calculator page includes an "Important Assumptions" section describing what the calculator does and does not account for. Calqora calculators are educational estimation tools - they do not replace advice from a financial advisor, medical professional, accountant, or attorney.

Updates

If a formula error is identified, we correct it as quickly as possible and note the change. See our Corrections Policy for how to report an issue.