Codewire vs Voltbox

Codewire is the fast, offline calculator set built for electricians and apprentices. No ads, no signup, no subscription. Every calculator runs on your phone, even with no signal. WHAT'S INSIDE - Voltage Drop. Single- or three-phase, copper or aluminum, with drop %, voltage at the load, and the smallest wire that holds your target. - Wire Ampacity. Adjusted for ambient heat and bundled conductors. - Conduit Fill. EMT, rigid, and PVC, with the 53 / 31 / 40% limits applied. - Conduit Bending. Offset, rolling offset, three- and four-bend saddle, 90 degree stub, and back-to-back, with per-size take-up. - Box Fill. Required volume from conductors, devices, clamps, and grounds. - Ohm's Law. Solve any two of V, I, R, and P. - Three-Phase Power and kVA to Amps. - Motor Full-Load Current by horsepower. - Unit Converter. AWG to mm2, kW to HP, F to C, ft to m, and more. THE BEND ANGLE LEVEL Turn your phone into a digital angle finder. Lay it on the conduit and read the bend angle live, hands-free, with a set-zero reference. Most apps charge for this. Codewire includes it free. SHOWS ITS WORK Every result has a tap-to-reveal with the formula and method behind it, so apprentices learn the why, not just the number. BUILT RIGHT - Works 100% offline. - No ads, ever. - No account, no tracking. Saved calculations stay on your device. - Clean, fast input designed for the field. FREE, NO ACCOUNT NEEDED - Voltage drop, wire ampacity, Ohm’s law, and conduit fill. CODEWIRE PRO (one-time in-app purchase) A single purchase unlocks the advanced tools: three-phase power, kVA to amps, motor FLC, conduit bending, box fill, the bend-angle level, saved calculations, and the full NEC reference tables. No subscription. Codewire is a reference tool. Always verify results against the code edition adopted by your jurisdiction and your AHJ. It is not a substitute for a licensed electrician.

Voltbox is a professional calculator toolkit for electricians, built around the NEC (National Electrical Code). Fast, accurate, and yours to own — pay once, keep it forever. 18 CALCULATORS Fundamentals (free) • Ohm's Law — voltage, current, resistance, power, series/parallel • Wire & Cable Sizing — NEC ampacity lookup Dwelling Load • Load Calculation — dwelling feeder/service sizing (NEC 220) • Range Demand — cooking appliance demand load (NEC 220.55) • Generator Sizing • Existing Load Evaluation — headroom check for adding new loads to an existing service Circuit Design • Voltage Drop — for any run length and load • Motor / Transformer Sizing — full-load amps per NEC 430 • Grounding & Bonding — NEC 250.66 / 250.122 • EV Charging — NEC 625 • HVAC Circuit Sizing • Feeder Tap Conductor — NEC 240.21(B) • Spa Bonding Exemption • Branch Circuit Sizing Installation • Conduit Fill — max conductors per conduit size, including bare wire • Box Fill — junction box conductor capacity • Conduit Bending — offset & 90° stub • Light Meter — jobsite illumination check against OSHA/egress/IES minimums WHY VOLTBOX • One-time purchase for Pro — never a subscription, never a recurring fee • Save and organize calculations by project • Built for the job site: fast, no clutter, no login screens, works with no signal • No account required — open the app and start calculating Ohm's Law and Wire Sizing are free. Unlock Pro once to get every other calculator. Voltbox is a reference tool based on the NEC. Always verify results against the current code edition adopted in your area and confirm compliance with a licensed electrician or your local inspector before performing any installation.