Methodology

Formula Selection Criteria

The foundation of every tool on CalcVault is its mathematical formula. Our selection criteria require that all foundational formulas be documented in official regulatory publications, scientific journals, or standardized industry frameworks. We do not use proprietary algorithms that cannot be independently verified by our users.

Handling Units and Precision

Unit handling is a critical component of our methodology. We standardize internal calculations to base units (e.g., meters, kilograms, days) and only convert values at the interface level when presenting results to the user. This minimizes floating-point errors and ensures consistency across different calculators. We also clearly state the precision level (e.g., rounded to two decimal places) in the results section of each tool.

Documenting Assumptions

Mathematical models often require assumptions, especially in finance (like an assumed inflation rate or market return). Our methodology mandates that all such assumptions are explicitly documented in the "How It Works" section of the calculator. Where possible, we make these variables adjustable by the user to reflect their unique circumstances rather than hardcoding averages.

Formula Versioning and Testing

As formulas evolve due to changing regulations, we employ a strict versioning system. Before a new formula goes live, it undergoes rigorous unit testing against known edge cases and historical data sets. Our testing process involves:

• Automated Testing: Running thousands of automated input permutations to ensure the mathematical logic never fails or produces an impossible output (like a negative time duration).
• Manual Verification: Cross-referencing results with official examples provided by regulatory bodies.

Vietnamese Regulatory Compliance

For localized calculators designed specifically for the Vietnamese context, our methodology includes a layer of regulatory compliance review. We source formulas directly from circulars and decrees issued by the Ministry of Finance, the Ministry of Labor, Invalids and Social Affairs, and the State Bank of Vietnam. This ensures that calculators handling local taxes, social insurance, or specific loan structures accurately reflect current Vietnamese law.

Last reviewed: 2026-07-18