About
Build: v0.7.3+20261027123958
This independent web tool implements selected ISO 14912:2025 procedures for complete gas composition fractions. Calculations run locally in the browser.
Standard and implementation
ISO 14912:2025 is titled Gas analysis — Conversion of gas mixture composition data. This implementation uses Annex C molar masses and second pressure virial data to convert complete compositions between mole, mass, and volume fractions. Specified pressure and temperature are used when volume fractions are involved.
The converter is not official or certified reference software. The current scope on the home page lists supported components, conditions, and exclusions.
Results and validation
The converted composition is the primary result. Normalization and property details remain available for inspection.
The converter is being developed toward broader coverage of ISO 14912. For limitations and conditions of use, see the Legal page.