WattCalculators: Global Electrical Engineering, Solar PV, EV Charging & Heat Pump Calculators
Free electrical engineering & solar calculators: NEC AWG & IEC mm² wire size and voltage drop, Solar PV & LiFePO4 battery sizing, kVA to Amps, EV charging time, and Heat Pump kW/BTU.
⚡ Quick Interactive Voltage Drop & Wire Size Calculator (Copper & Aluminum)
Recommended Copper Size (≤3% Drop)4 AWG (25 mm²)
Actual Voltage Drop3.12 V (1.30%)
Circuit Power Capacity14.40 kW
Recommended Breaker (125%)80 A
🇺🇸 NEC Wire Size & Voltage Drop (AWG — 120V, 240V, 208V, 480V)
Pre-calculated American Wire Gauge (AWG & kcmil) conductor sizing meeting both NEC Table 310.16 (75°C) ampacity and ≤3% branch/feeder voltage drop:
15 Amp Wire Size at 100 ft (240V)20 Amp Wire Size at 100 ft (240V)30 Amp Wire Size at 100 ft (240V)40 Amp Wire Size at 100 ft (240V)50 Amp Wire Size at 100 ft (240V)60 Amp Wire Size at 100 ft (240V)80 Amp Wire Size at 100 ft (240V)100 Amp Wire Size at 100 ft (240V)125 Amp Wire Size at 100 ft (240V)150 Amp Wire Size at 100 ft (240V)200 Amp Wire Size at 100 ft (240V)400 Amp Wire Size at 100 ft (240V)
🇪🇺🇬🇧🇦🇺 IEC 60364 Metric Cable Sizing (mm² — 230V, 400V, 415V, 48V DC)
International metric cable cross-section calculations (1.5 mm² to 400 mm²) for Europe, United Kingdom, Australia, and industrial three-phase grids:
10A Cable Size at 30m (400V IEC)16A Cable Size at 30m (400V IEC)20A Cable Size at 30m (400V IEC)25A Cable Size at 30m (400V IEC)32A Cable Size at 30m (400V IEC)40A Cable Size at 30m (400V IEC)50A Cable Size at 30m (400V IEC)63A Cable Size at 30m (400V IEC)80A Cable Size at 30m (400V IEC)100A Cable Size at 30m (400V IEC)125A Cable Size at 30m (400V IEC)160A Cable Size at 30m (400V IEC)
🇩🇪🇸🇪🇳🇴🇩🇰 DACH & Scandinavian Native Engineering Hubs (VDE, SS 436, NEK 400, DS)
Native-language electrical cable cross-section & voltage drop calculators for Germany, Sweden, Norway, and Denmark:
🇩🇪 16A Kabelquerschnitt 25m (400V)🇩🇪 25A Kabelquerschnitt 25m (400V)🇩🇪 32A Kabelquerschnitt 25m (400V)🇩🇪 40A Kabelquerschnitt 25m (400V)🇩🇪 63A Kabelquerschnitt 25m (400V)🇩🇪 100A Kabelquerschnitt 25m (400V)🇸🇪 16A Kabelarea 25m (400V)🇸🇪 25A Kabelarea 25m (400V)🇸🇪 32A Kabelarea 25m (400V)🇸🇪 40A Kabelarea 25m (400V)🇸🇪 63A Kabelarea 25m (400V)🇸🇪 100A Kabelarea 25m (400V)🇳🇴 16A Kabeltverrsnitt 25m (230V)🇳🇴 25A Kabeltverrsnitt 25m (230V)🇳🇴 32A Kabeltverrsnitt 25m (230V)🇳🇴 40A Kabeltverrsnitt 25m (230V)🇳🇴 63A Kabeltverrsnitt 25m (230V)🇳🇴 100A Kabeltverrsnitt 25m (230V)🇩🇰 16A Kabeltværsnit 25m (400V)🇩🇰 25A Kabeltværsnit 25m (400V)🇩🇰 32A Kabeltværsnit 25m (400V)🇩🇰 40A Kabeltværsnit 25m (400V)🇩🇰 63A Kabeltværsnit 25m (400V)🇩🇰 100A Kabeltværsnit 25m (400V)
☀️ Solar PV Array (kWp), 440W Panel Count & LiFePO4 Battery Storage
Location-calibrated solar sizing across 60 US states, European countries, Nordic cities, and Australia:
🏭 Industrial Power Conversion (kVA & kW to Amps)
🚗❄️ EV Charger Time & Heat Pump Thermal Load (kW / BTU/h)
60 kWh EV Battery on 7.4 kW Charger75 kWh EV Battery on 11 kW Charger77 kWh EV Battery on 11 kW Charger82 kWh EV Battery on 11.5 kW Charger100 kWh EV Battery on 22 kW Charger75 kWh EV Battery on 150 kW Charger90 kWh EV Battery on 250 kW Charger100 kWh EV Battery on 350 kW Charger100 m² Heat Pump (NORDIC)140 m² Heat Pump (NORDIC)160 m² Heat Pump (CENTRAL)200 m² Heat Pump (US)120 m² Heat Pump (UK)180 m² Heat Pump (AUSTRALIA)