How to calculate the electrical service load for a residential panel — the NEC Article 220 standard method and optional method. Required for service sizing and permit applications.
How to calculate heating and cooling loads using Manual J — the ACCA standard method. Covers the inputs, the math, and why rule-of-thumb sizing fails.
How to calculate conduit fill correctly using NEC Chapter 9 tables — maximum fill percentages, wire area lookup, and common mistakes that fail inspection.
How to size water supply pipes, drain/waste/vent systems, and gas piping correctly — with the UPC and IRC references behind each calculation.
Step-by-step concrete volume calculations for common pours — footings, slabs, walls, and columns. Includes waste factor guidance and ordering tips.
How to size supply and return ducts correctly using the equal friction method — the ASHRAE standard approach used by HVAC professionals.
CalcRig