All Trades41 calculators
Trade Calculators
41 transparent planning tools
Amp conversions, concrete, roofing, stair geometry, voltage drop, load calculations, pipe sizing, and more — all shown with their math.
Browse calculatorsHVAC
EPA Section 608 Practice Test
Free 25-question sampler
Built directly from federal regulations (40 CFR Part 82). Every answer explained and linked to its official source.
25 questionsStart practicing
All Trades
Estimate Writer
Rough notes → clean estimates
Turn rough job notes into professional estimate drafts in seconds. HVAC, plumbing, electrical, and general trade work.
Free to useWrite an estimate
All Trades
Contractor Blog
Guides for quoting jobs
Cross-industry articles to help contractors write clean, professional, and profitable quotes that win more work.
Free articlesRead guides
Electrical
Become an Electrician
All 50 states + DC
Find your state's official electrical licensing board, requirements, and application info. One source for every jurisdiction.
51 boardsFind your state board
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