About

Build: v0.8.3+20260817093018

A public methane number calculator for gas mixtures, built around ISO 17507-1:2025.

The app is intended for engineers, laboratories, and gas professionals who need a practical way to evaluate calculated methane number for natural gas, biomethane, biogas, and hydrogen-containing gas mixtures.

The calculation core is considered feature-complete for the ISO 17507-1:2025 calculated methane number method as currently implemented and understood. The web application around it is still being refined, including user interface, documentation, validation presentation, and operational details.

The calculator accepts volume, mole, or mass fractions and converts the input to the volume-fraction basis used by the ISO 17507-1 calculation method.

The Annex A.10 comparison page shows additional validation data for users who know the standard and want to inspect reference examples, spread values, and selected or eliminated ternary systems.

The calculator is currently available free of charge while the application is being tested, reviewed, and improved. Access conditions may change in the future, including the introduction of paid access, subscription plans, or usage limits.