How they are built
Formulas from the NEC, the CEC and standard references, coded in plain JavaScript that runs in your browser. Nothing you type leaves your device.
Calculators · NEC and CEC
Calculators
Five tools I use for early checks on real jobs, each written up with its formula, its code reference and its limits. Results update as you type, and every tool can copy a link to your inputs.
Free. No sign-up. Not sealed engineering. By Ali Mazloum, P.Eng. (NS, AB), P.E. (TX), PMP
NEC 215 · CEC 8-102 Voltage drop Smallest conductor that keeps the drop inside your limit. AC or DC, copper or aluminum.NEC Article 220 Service load Residential demand load and minimum service size, standard method.Renewables Solar PV Array capacity, annual energy and savings from roof area and sun hours.Renewables Wind energy Turbine power, swept area and annual output, with the Betz limit.Estimating Construction cost Class 5 order of magnitude by building type, with a trade breakdown.
What they are for
Early checks: a bid review, a feasibility number, a sanity check on a drawing. Each page explains the method so you can defend the number.
What they are not
Sealed engineering. They leave out ampacity, short-circuit, shading and site conditions on purpose. A licensed engineer signs the real design.
FAQ
Are the calculators free?
Yes. No account, no email, no limits. They are for education and early design checks, not sealed engineering.
Can you stamp drawings?
No. I do not seal drawings or take on engineering, estimating or consulting work through this site. The calculators are for education and early checks only.
