Trust & Governance

International Standards Policy

Last updated: June 16, 2026

AllKindsOfConverters bases its conversion factors and unit definitions on internationally recognized measurement standards. This page explains which standards we use and how we reconcile differences between them.

Primary references

  • BIPM — SI Brochure (currently 9th edition). The definitive source for SI base units, derived units, prefixes and constants.
  • NIST SP 811 — US national guide for the use of SI, including conversion factors against US customary units.
  • ISO 80000 — Quantities and units. A multi-part standard covering nomenclature, symbols and notation across science and engineering.
  • IEC 60027 / IEC 80000-13 — Binary prefixes (KiB, MiB, GiB …) for digital storage and information theory.
  • IUPAC Gold Book — Chemistry terminology and physical constants.
  • ISO 4217 — Currency codes used in the FX converter.

Reconciling differences

Where multiple standards address the same quantity, we follow this priority:

  1. The SI Brochure for base units, prefixes and physical constants.
  2. ISO 80000 for symbols and notation.
  3. NIST SP 811 for SI ↔ US customary conversion factors.
  4. National weights-and-measures legislation for legal-for-trade conversions in specific jurisdictions.

Evolving standards

Measurement standards evolve. The 2019 SI redefinition replaced the artifact kilogram with a definition based on the Planck constant. The US survey foot was phased out in 2023 in favor of the international foot. We track these changes and update affected tools, with a public note where the change is material.

Limits of this policy

Following an international standard does not certify our calculations under that standard, nor does it guarantee fitness for a regulated use case. For regulated applications, consult the controlling authority and primary source documents.