Voltage Drop Calculator. vs Volt Drop Check & Plug

Perform accurate Voltage Drop and Wire Sizing calculations for both NEC® (National Electrical Code) and IEC standards. Built for electricians, engineers, and contractors who need reliable results on the go. Voltage Drop Calculator • Dual standards: Switch between NEC (AWG/Imperial) and IEC (mm²/Metric) • Enter voltage, current, run length, and power factor • Supports continuous load (125%), grouping, and ambient temperature corrections • Copper or Aluminum conductors for single-phase and three-phase systems • Detailed results including ampacity, derating, voltage drop, and load voltage • Automatic compliance checks (e.g., ≤ 3% for branch circuits) Wire Size Calculator (Reverse) • Calculates required wire size for a target voltage drop % • Suggests optimal AWG, kcmil, or mm² • Uses NEC Chapter 9, Table 9 (AC impedance) with DC fallback Professional Tools • Wire converter (AWG/kcmil ↔ mm²) • Generate and share PDF reports • Handy electrical formula cards • Localized in English, Spanish, French, German, Italian, Dutch, Portuguese, and Chinese

Volt Drop Check & Plug is an iPhone-only electrical calculation toolkit for field electricians, maintenance technicians, and design engineers. Stop juggling paper tables, calculators, and spreadsheets — switch between tabs and get the answer you need in seconds. ■ What's inside 1) Voltage Drop Calculator • Inputs: supply voltage, load current (or power in W), cable length, conductor material (copper / aluminum), insulation (PVC 70°C, XLPE 90°C, heat-resistant PVC 105°C), circuit type (DC / 1-phase 2-wire, 3-phase 3-wire), power factor, and optional reactance. • Outputs: ΔV, drop %, terminal voltage, loop resistance, and assumed conductor temperature. • GOOD / CAUTION / NG verdict badge with a one-line explanation, improvement suggestions, risk notes, and basis notes. • Round-trip ×2 applied automatically for DC / single-phase; √3 factor applied for three-phase. 2) Cable Size Selection (reverse calculation) • From load current, voltage, cable length, allowable drop %, material, circuit type, power factor, and ambient temperature, get the minimum required conductor area and a recommended cable size. • Side-by-side comparison of common sizes with PASS / FAIL / BEST indicators. 3) Ampacity Calculator • From conductor material, size, installation method (free air / in conduit / bundled), insulation type, ambient temperature, and grouping count, see base ampacity with temperature and grouping correction factors. • Corrected ampacity plus a per-installation-method summary. 4) Breaker Selection Guide • From circuit current, circuit voltage, usage (general load / motor / lighting / IT·server), and phase (single / three), get a recommended rating (AT), frame size (AF), and type (MCCB / MCB / ELCB). • Earth-leakage (ELCB) recommendation is highlighted automatically where appropriate. Includes a type guide. 5) Power Calculator (W ↔ VA ↔ kVA ↔ var) • Convert between active power (W / kW), apparent power (VA / kVA), reactive power (var / kvar), and phase angle φ from voltage, current, and power factor. • Three input modes: V×A, W, or VA. Single-phase / three-phase switchable. 6) NEMA / IEC Plug Quick Reference • A searchable cheat sheet for plugs and connectors — useful for overseas sites and imported equipment. Filter by code, voltage, and more. ■ Designed for the field • One-tap Japanese / English UI toggle (selection is remembered). • All calculations run on-device — works reliably even with poor signal. • Clear separation of inputs and results, with verdict badges and plain-language notes. • iPhone-first layout tuned for one-handed use. ■ Great for • Field electricians and contractors • Facility and maintenance technicians • Plant and building-services engineers • Solar, energy-storage, and EV-charging designers • Teams working with imported or overseas equipment • Electrical students and trainees ■ Important Results are reference values based on generic targets (e.g., 3% voltage-drop goal, 5% maximum). Always follow your local codes, internal standards, and equipment specifications for actual design and installation.