The ultimate guide to 40+ free construction calculators for contractors. Concrete, roofing, electrical, HVAC, and more.
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Updated
Mar 8, 2026 - HTML
The ultimate guide to 40+ free construction calculators for contractors. Concrete, roofing, electrical, HVAC, and more.
Free HVAC Load Calculator - Manual J simplified residential heating & cooling BTU calculator
Open-source parser for construction cost-book PDFs (Craftsman National Construction Estimator + others). Extracts material/labor line items into structured JSON or CSV. The parser InsightEngine SaaS runs on, free for everyone.
Documentation and releases for workflow app titled: Gutter App
Documentation and releases for workflow app titled: Electrician App
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