TrueOhm vs Voltage Drop Pro

TrueOhm is a fast, free electrical calculator built for electricians, apprentices, and engineers. Five powerful calculators in one app: • Ohm's Law Wheel — Enter any two of voltage, current, resistance, or power and instantly solve the other two. • AC Power — Calculate real power, apparent power, current, and voltage for single-phase and three-phase systems. • Power Triangle — Solve the relationship between kW, kVAR, kVA, power factor, and phase angle. • Energy Cost — Estimate energy consumption and cost for any load over any run time. • Efficiency — Calculate motor or system efficiency from input and output power. Every calculation shows its work — tap "How this was calculated" to see the exact formulas and substitutions used. Built-in sanity checks warn you about impossible values without blocking your workflow. Designed for the field. No ads. No subscriptions. Just fast, accurate calculations from 509 Electric.

Voltage Drop Pro calculates voltage drop per NEC 2023 Article 210.19 and 215.2 — the code sections that determine if your conductor run keeps voltage drop within acceptable limits. Works offline. No subscription. One-time purchase. WHAT IT CALCULATES - Branch circuits (210.19) and feeders (215.2) - Copper (K=10.4) and aluminum (K=17.0) conductors at 75°C - All wire sizes — 14 AWG through 500 kcmil - System voltages from 120V to 480V VERDICTS BACKED BY CODE Compares your voltage drop percentage against the NEC-recommended 3% branch/feeder max and 5% combined max. Get an instant PASS or FAIL — with the actual voltage drop, margin, and wire data shown. BUILT FOR THE FIELD No ads. No cloud. No account required. Designed for electricians who need the answer in seconds, not after a signup flow. PART OF THE FIELDMETRIC SUITE Also available: Box Fill Pro (NEC box fill) and Conduit Fill Pro (NEC conduit fill calculations).