NEWFieldDojo Pro is live→App StoreGoogle Play

About FieldDojo

Last updated: September 3, 2026

FieldDojo is a mobile calculator app for trade professionals — electrical, HVAC, plumbing, and construction. 57 calculators, every result stamped with the code section it came from, all of it working offline in a basement.

Who builds it

FieldDojo is designed, built, and maintained by NOTchip, an indie agency building mobile apps, full-stack systems, and DevOps solutions for clients worldwide. There is no growth team, no ad network, and no data brokerage behind it — the product makes money one way: optional Pro purchases through the App Store and Google Play.

A note on the App Store listing: FieldDojo currently ships from the personal Apple developer account of Raman Halder, NOTchip’s founder — the same developer who builds the app. Starting on a founder’s account is common for indie apps; the listing will move to a company (LLC) developer account soon. Nothing changes for you when it does — same team, same app, same policies, and purchases carry over.

How the math is validated

Trade math is safety-adjacent, so we treat accuracy as a feature:

  • Every formula traces to a published source. We maintain an internal knowledge base of building codes, standards, and formulas — NEC tables, ASHRAE and ACCA methods, UPC/IPC fixture-unit tables, NFPA 54 gas sizing, IRC/IECC climate and insulation requirements, and ACI 318 for concrete. Calculator logic is written against those pages, not from memory.
  • The citation ships with the result. Every answer in the app shows the exact code reference it was computed from (for example NEC 310.16 · Wire ampacity), so you can open the book and check us.
  • Codes change; the app updates. When a jurisdiction adopts a new edition, updated tables reach the app through regular releases — annual code-table updates will be part of Pro’s yearly plan for exactly this reason.

The honest limits: FieldDojo is a calculation aid, not a substitute for the code book or your judgment. Local amendments vary by jurisdiction, and the authority having jurisdiction (AHJ) always has the final word. Verify results against the code edition your inspector enforces.

The product principles

  • Offline-first. Every calculation runs on-device. Job sites don’t have bars.
  • Free means free. All 57 calculators, forever, no ads, on both stores. Pro adds convenience — unlimited history, cloud sync, PDF export, unlimited projects — not access.
  • No data games. Calculations stay on your phone unless you opt into cloud sync. We sell nothing to anyone.

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