Voltage Drop Calculator. vs Panel Planner

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

Plan, visualize, and manage your home's electrical system — right from your iPhone. Circuit Breaker Panel is an interactive residential electrical panel simulator that lets you map out every circuit in your home, track real-time current loads, and plan new circuits before you ever call an electrician. BUILD YOUR PANEL Install single-pole (120V) and double-pole (240V) breakers in any configuration. Choose from 15A, 20A, 30A, 40A, 50A, and 60A ratings. Support for 24, 30, and 40-slot panels with 100A, 150A, 200A, and 400A main breakers. ADD YOUR DEVICES Populate each circuit with the real appliances and devices in your home. Choose from 20 common presets — refrigerator, HVAC, EV charger, dryer, and more — or enter any custom wattage. Toggle devices on and off to simulate real-world usage scenarios. LIVE LOAD CALCULATIONS Current draw is calculated automatically for every circuit (Amps = Watts ÷ Voltage). Watch each breaker's load bar update in real time as you switch devices on and off. COLOR-CODED SAFETY STATUS Know at a glance which circuits are safe and which are at risk: Green glow — circuit is within safe range (under 70% load) Yellow glow — load is climbing, approaching capacity (70–90%) Red pulsing glow — circuit is overloaded, breaker would trip (over 90%) SAVE UP TO 10 PANELS Save and restore up to 10 complete panel configurations. Perfect for planning a renovation, comparing layouts, or managing panels across multiple properties. DESIGNED FOR CLARITY A realistic panel enclosure with a center bus bar, physical breaker switches, and load bars on every circuit give you an intuitive feel for your home's electrical system — no electrical engineering degree required. FULLY OFFLINE & PRIVATE No account. No internet connection. No data collection of any kind. Your panel configurations are stored only on your device.