NIST Guide to the SI
NIST Special Publication 811 and conversion appendicesExact SI and US customary conversion definitions used by the unit engine.
Educational reference
Sources
Technical sources for formulas, material assumptions, unit definitions, and US and Canadian standards-publication status.
Stable scientific and technical sources
NBS/NIST conductor references
Copper wire tables and technical backgroundTechnical background for copper resistivity and resistance-temperature behavior. PowerTotals lists its representative constants separately from the formulas.
NBS copper and aluminum conductivity data
The electrical conductivity of commercial copperThe publication reports 20°C copper data and commercial hard-drawn aluminum resistivity data used to check the representative conductor constants.
US Department of Defense wire specification index
AWG nominal geometry specification recordThe implementation calculates nominal solid-wire geometry from the AWG mathematical relationship.
IBM Plex
Official IBM Plex repositorySelf-hosted Sans and Mono typefaces distributed under the SIL Open Font License 1.1.
Tabler visual convention
Tabler IconsThe interface uses a small, original inline implementation of the Tabler-style two-pixel stroke convention; no mixed icon pack or emoji UI.
Standards-publication status sources
These records track public metadata and links only. PowerTotals does not reproduce NFPA 70 or CSA C22.1 text, diagrams, values, or tables.
NFPA 70 - National Electrical Code publication status
Publisher: National Fire Protection Association
Jurisdiction: US
Status: NFPA LiNK lists the 2026 edition alongside prior editions.
Verified:
NFPA LiNK API developer status
Publisher: National Fire Protection Association
Jurisdiction: US
Status: The official developer page says Coming Soon. No code-content integration is active.
Verified:
CSA C22.1 Canadian Electrical Code, Part I publication status
Publisher: CSA Group
Jurisdiction: Canada
Status: The verified public CSA sources identify the 2024 edition. Check the official catalogue for the latest status.
Verified: