Every formula
has a source.
We verify every calculation against primary international standards. Not approximations. Not memory. Published, citable, verifiable sources.
Our Verification Process
Primary Source First
Every formula begins with a primary source — a published international standard, peer-reviewed paper, or official government publication. We never use secondary sources like Wikipedia, forums, or general-purpose websites as the basis for a formula.
- NIST SP 811 for unit conversions
- ISO 80000 for mathematical notation
- BIPM SI Brochure for base units
- IEEE standards for electrical formulas
Independent Verification
After coding the formula, we test it against multiple known reference values from the original source. For example, the kg-to-lbs formula is tested against the exact value in NIST SP 811 (1 kg = 2.20462262185 lb) and verified to 11 significant figures.
- Test against published reference tables
- Cross-check with physical constants
- Verify edge cases (0, negatives, large values)
- Compare results with official conversion tools
Precision & Rounding Policy
We use IEEE 754 double-precision floating-point arithmetic throughout — the same standard used in scientific computing. Results are shown to a meaningful number of decimal places, not truncated arbitrarily. The raw calculation is never rounded before display.
- IEEE 754-2019 floating-point standard
- Display precision matches source precision
- No intermediate rounding in calculations
- Scientific notation for very large/small results
Source Citation on Every Page
Every calculator page displays the formula source by name, with a direct link to the original document. This is not decoration — it means you can independently verify any result against the same source we used. Transparency is non-negotiable.
- Source name shown on every tool page
- Direct link to original publication
- Formula displayed in standard notation
- Methodology page linked from every tool
Standards We Reference
NIST Special Publication 811
National Institute of Standards and Technology — Guide for the Use of the International System of Units (SI), 2008 Edition
ISO 80000-2
International Organization for Standardization — Mathematical Signs and Symbols, 2019 Edition
BIPM SI Brochure (9th Edition)
International Bureau of Weights and Measures — The International System of Units
IEC 60027-1
International Electrotechnical Commission — Letter Symbols for Electrical Engineering
Found an error?
If you believe a formula or result is incorrect, please report it. We take accuracy seriously — every report is reviewed within 24 hours and corrected immediately if confirmed.
Report an Error →