Credits and licences

Last updated 2026-10-11

Our own code

The tools and page layouts are written for this site. The pages make no requests to other servers.

The calculators use textbook formulas and published constants, typed into our own code:

Power relations for DC, single-phase and balanced three-phase circuits (P = √3 × V × I × PF and related forms), Ohm’s law, and power factor correction Qc = P (tan φ1 − tan φ2).
Conductor sizes: AWG diameters from the ASTM B258 definition; kcmil sizes; IEC 60228 nominal cross-sections.
Conductor resistance from resistivity: annealed copper 0.017241 Ω·mm²/m (100 % IACS), aluminium 0.028264 Ω·mm²/m, with temperature coefficients 0.00393 and 0.00403 per K.
Code rules are cited by section number only (for example NEC 210.20(A) for the 125 % continuous-load factor, 240.6(A) standard ratings, 430.52 motor protection percentages, 220.82 dwelling load). Code tables such as conductor ampacity are not reproduced.
Short-circuit current by the transformer impedance (infinite-bus) and point-to-point methods.

No third-party code, fonts or data files are loaded by the pages (data/credits.json, rendered below).