About this website
BuildWire Calc is a phone app of offline trade calculators for people who work on site; they keep working with no signal. Electrical: voltage drop, wire size, breaker size, load, Ohm's law, three-phase power, conduit bending. Construction: concrete slab, footing, rebar, roof pitch, stairs. HVAC: BTU, CFM, duct size, superheat. Save a job and share it as PDF, CSV or text. No ads, no account. Free tier; Pro unlocks the rest.
Key features
- Electrical calculators: voltage drop, wire size, breaker size, Ohm's law
- Construction calculators: concrete slab, footing, rebar, stairs
- HVAC calculators: BTU, CFM, duct size, superheat
- Save jobs and share as PDF, CSV or text
- Works offline with no signal, no ads, no account
Who is this website for?
Electricians, builders and HVAC technicians who need quick trade calculations on site.
What can visitors do here?
Work out voltage drop or wire size for a circuit, size a concrete slab or footing, or calculate BTU for a room, then save the job and share it as a PDF.
What makes it different?
Calculators for electrical, construction and HVAC work in one app that keeps working offline with no signal.
